Implement in-process multi-dataset sync isolation across core, network, persistence, and tests

docs/architecture.md

@@ -30,6 +30,13 @@ To optimize reconnection, each node maintains a **Snapshot** of the last known s
 - If the chain hash matches, they only exchange the delta.
 - This avoids re-processing the entire operation history and ensures efficient gap recovery.
 
+### Multi-Dataset Sync
+CBDDC supports per-dataset sync pipelines in one process.
+
+- Dataset identity (`datasetId`) is propagated in protocol and persistence records.
+- Each dataset has independent oplog reads, confirmation state, and maintenance cadence.
+- Legacy peers without dataset fields interoperate on `primary`.
+
 ### Peer-Confirmed Oplog Pruning
 CBDDC maintenance pruning now uses a two-cutoff model:
 

docs/features/README.md

@@ -8,6 +8,7 @@ This index tracks CBDDC major functionality. Each feature has one canonical docu
 - [Peer-to-Peer Gossip Sync](peer-to-peer-gossip-sync.md)
 - [Secure Peer Transport](secure-peer-transport.md)
 - [Peer-Confirmed Pruning](peer-confirmed-pruning.md)
+- [Multi-Dataset Sync](multi-dataset-sync.md)
 
 ## Maintenance Rules
 

docs/features/multi-dataset-sync.md

@@ -0,0 +1,67 @@
+# Multi-Dataset Sync
+
+## Summary
+
+CBDDC can run multiple sync pipelines inside one process by assigning each pipeline a `datasetId` (for example `primary`, `logs`, `timeseries`).
+Each dataset pipeline has independent oplog state, vector-clock reads, peer confirmation watermarks, and maintenance scheduling.
+
+## Why Use It
+
+- Keep primary business data sync latency stable during high telemetry volume.
+- Isolate append-only streams (`logs`, `timeseries`) from CRUD-heavy collections.
+- Roll out incrementally using runtime flags and per-dataset enablement.
+
+## Configuration
+
+Register dataset options and enable the runtime coordinator:
+
+```csharp
+services.AddCBDDCSurrealEmbedded<SampleDocumentStore>(sp => options)
+    .AddCBDDCSurrealEmbeddedDataset("primary", o =>
+    {
+        o.InterestingCollections = ["Users", "TodoLists"];
+    })
+    .AddCBDDCSurrealEmbeddedDataset("logs", o =>
+    {
+        o.InterestingCollections = ["Logs"];
+        o.SyncLoopDelay = TimeSpan.FromMilliseconds(500);
+    })
+    .AddCBDDCSurrealEmbeddedDataset("timeseries", o =>
+    {
+        o.InterestingCollections = ["Timeseries"];
+        o.SyncLoopDelay = TimeSpan.FromMilliseconds(500);
+    })
+    .AddCBDDCNetwork<StaticPeerNodeConfigurationProvider>();
+
+services.AddCBDDCMultiDataset(options =>
+{
+    options.EnableMultiDatasetSync = true;
+    options.EnableDatasetPrimary = true;
+    options.EnableDatasetLogs = true;
+    options.EnableDatasetTimeseries = true;
+});
+```
+
+## Wire and Storage Compatibility
+
+- Protocol messages include optional `dataset_id` fields.
+- Missing `dataset_id` is treated as `primary`.
+- Surreal persistence records include `datasetId`; legacy rows without `datasetId` are read as `primary`.
+
+## Operational Notes
+
+- Each dataset runs its own `SyncOrchestrator` instance.
+- Maintenance pruning is dataset-scoped (`datasetId` + cutoff).
+- Snapshot APIs support dataset-scoped operations (`CreateSnapshotAsync(stream, datasetId)`).
+
+## Migration
+
+1. Deploy with `EnableMultiDatasetSync = false`.
+2. Enable multi-dataset mode with only `primary` enabled.
+3. Enable `logs`, verify primary sync SLO.
+4. Enable `timeseries`, verify primary sync SLO again.
+
+## Rollback
+
+- Set `EnableDatasetLogs = false` and `EnableDatasetTimeseries = false` first.
+- If needed, set `EnableMultiDatasetSync = false` to return to the single `primary` sync path.

docs/persistence-providers.md

@@ -221,6 +221,14 @@ services.AddCBDDCCore()
     });
 ```
 
+### Multi-Dataset Partitioning
+
+Surreal persistence now stores `datasetId` on oplog, metadata, snapshot metadata, confirmation, and CDC checkpoint records.
+
+- Composite indexes include `datasetId` to prevent cross-dataset reads.
+- Legacy rows missing `datasetId` are interpreted as `primary` during reads.
+- Dataset-scoped store APIs (`ExportAsync(datasetId)`, `GetOplogAfterAsync(..., datasetId, ...)`) enforce isolation.
+
 ### CDC Durability Notes
 
 1. **Checkpoint semantics**: each consumer id has an independent durable cursor (`timestamp + hash`).

docs/runbook.md

@@ -27,6 +27,15 @@ Capture these artifacts before remediation:
 - Current runtime configuration (excluding secrets).
 - Most recent deployment identifier and change window.
 
+## Multi-Dataset Gates
+
+Before enabling telemetry datasets in production:
+
+1. Enable `primary` only and record baseline primary sync lag.
+2. Enable `logs`; confirm primary lag remains within SLO.
+3. Enable `timeseries`; confirm primary lag remains within SLO.
+4. If primary SLO regresses, disable telemetry datasets first before broader rollback.
+
 ## Recovery Plays
 
 ### Peer unreachable or lagging

samples/ZB.MOM.WW.CBDDC.Sample.Console/ConsoleInteractiveService.cs

@@ -112,6 +112,7 @@ public class ConsoleInteractiveService : BackgroundService
         System.Console.WriteLine("Commands:");
         System.Console.WriteLine("  [p]ut, [g]et, [d]elete, [f]ind, [l]ist peers, [q]uit");
         System.Console.WriteLine("  [n]ew (auto), [s]pam (5x), [c]ount, [t]odos");
+        System.Console.WriteLine("  log [count], ts [count] (append telemetry load)");
         System.Console.WriteLine("  [h]ealth, cac[h]e");
         System.Console.WriteLine("  [r]esolver [lww|merge], [demo] conflict");
     }
@@ -156,8 +157,12 @@ public class ConsoleInteractiveService : BackgroundService
         {
             int userCount = _db.Users.FindAll().Count();
             int todoCount = _db.TodoLists.FindAll().Count();
+            int logCount = _db.Logs.FindAll().Count();
+            int timeseriesCount = _db.Timeseries.FindAll().Count();
             System.Console.WriteLine($"Collection 'Users': {userCount} documents");
             System.Console.WriteLine($"Collection 'TodoLists': {todoCount} documents");
+            System.Console.WriteLine($"Collection 'Logs': {logCount} documents");
+            System.Console.WriteLine($"Collection 'Timeseries': {timeseriesCount} documents");
         }
         else if (input.StartsWith("p"))
         {
@@ -212,6 +217,42 @@ public class ConsoleInteractiveService : BackgroundService
             var results = _db.Users.Find(u => u.Age > 28);
             foreach (var u in results) System.Console.WriteLine($"Found: {u.Name} ({u.Age})");
         }
+        else if (input.StartsWith("log", StringComparison.OrdinalIgnoreCase))
+        {
+            int count = ParseCount(input, 100);
+            for (var i = 0; i < count; i++)
+            {
+                var entry = new TelemetryLogEntry
+                {
+                    Id = Guid.NewGuid().ToString("N"),
+                    Level = i % 25 == 0 ? "Warning" : "Information",
+                    Message = $"sample-log-{DateTimeOffset.UtcNow:O}-{i}",
+                    CreatedUtc = DateTime.UtcNow
+                };
+                await _db.Logs.InsertAsync(entry);
+            }
+
+            await _db.SaveChangesAsync();
+            System.Console.WriteLine($"Appended {count} log entries.");
+        }
+        else if (input.StartsWith("ts", StringComparison.OrdinalIgnoreCase))
+        {
+            int count = ParseCount(input, 100);
+            for (var i = 0; i < count; i++)
+            {
+                var point = new TimeseriesPoint
+                {
+                    Id = Guid.NewGuid().ToString("N"),
+                    Metric = i % 2 == 0 ? "cpu" : "latency",
+                    Value = Random.Shared.NextDouble() * 100,
+                    RecordedUtc = DateTime.UtcNow
+                };
+                await _db.Timeseries.InsertAsync(point);
+            }
+
+            await _db.SaveChangesAsync();
+            System.Console.WriteLine($"Appended {count} timeseries points.");
+        }
         else if (input.StartsWith("h"))
         {
             var health = await _healthCheck.CheckAsync();
@@ -283,6 +324,13 @@ public class ConsoleInteractiveService : BackgroundService
         }
     }
 
+    private static int ParseCount(string input, int fallback)
+    {
+        string[] parts = input.Split(' ', StringSplitOptions.RemoveEmptyEntries);
+        if (parts.Length < 2) return fallback;
+        return int.TryParse(parts[1], out int parsed) && parsed > 0 ? parsed : fallback;
+    }
+
     private async Task RunConflictDemo()
     {
         System.Console.WriteLine("\n=== Conflict Resolution Demo ===");

samples/ZB.MOM.WW.CBDDC.Sample.Console/Program.cs

@@ -4,6 +4,7 @@ using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
 using Serilog;
 using System.Text.Json;
+using ZB.MOM.WW.CBDDC.Core;
 using ZB.MOM.WW.CBDDC.Core.Network;
 using ZB.MOM.WW.CBDDC.Core.Storage;
 using ZB.MOM.WW.CBDDC.Core.Sync;
@@ -62,11 +63,22 @@ internal class Program
         Directory.CreateDirectory(dataPath);
         string databasePath = Path.Combine(dataPath, $"{nodeId}.rocksdb");
         string surrealDatabase = nodeId.Replace("-", "_", StringComparison.Ordinal);
+        var multiDatasetOptions = builder.Configuration
+                                      .GetSection("CBDDC:MultiDataset")
+                                      .Get<MultiDatasetRuntimeOptions>()
+                                  ?? new MultiDatasetRuntimeOptions
+                                  {
+                                      EnableMultiDatasetSync = true,
+                                      EnableDatasetPrimary = true,
+                                      EnableDatasetLogs = true,
+                                      EnableDatasetTimeseries = true
+                                  };
 
         // Register CBDDC services with embedded Surreal (RocksDB).
         builder.Services.AddSingleton<ICBDDCSurrealSchemaInitializer, SampleSurrealSchemaInitializer>();
         builder.Services.AddSingleton<SampleDbContext>();
-        builder.Services.AddCBDDCCore()
+        builder.Services
+            .AddCBDDCCore()
             .AddCBDDCSurrealEmbedded<SampleDocumentStore>(_ => new CBDDCSurrealEmbeddedOptions
             {
                 Endpoint = "rocksdb://local",
@@ -74,8 +86,30 @@ internal class Program
                 Namespace = "cbddc_sample",
                 Database = surrealDatabase
             })
+            .AddCBDDCSurrealEmbeddedDataset(DatasetId.Primary, options =>
+            {
+                options.InterestingCollections = ["Users", "TodoLists"];
+            })
+            .AddCBDDCSurrealEmbeddedDataset(DatasetId.Logs, options =>
+            {
+                options.InterestingCollections = ["Logs"];
+            })
+            .AddCBDDCSurrealEmbeddedDataset(DatasetId.Timeseries, options =>
+            {
+                options.InterestingCollections = ["Timeseries"];
+            })
             .AddCBDDCNetwork<StaticPeerNodeConfigurationProvider>(); // useHostedService = true by default
 
+        if (multiDatasetOptions.EnableMultiDatasetSync)
+            builder.Services.AddCBDDCMultiDataset(options =>
+            {
+                options.EnableMultiDatasetSync = multiDatasetOptions.EnableMultiDatasetSync;
+                options.EnableDatasetPrimary = multiDatasetOptions.EnableDatasetPrimary;
+                options.EnableDatasetLogs = multiDatasetOptions.EnableDatasetLogs;
+                options.EnableDatasetTimeseries = multiDatasetOptions.EnableDatasetTimeseries;
+                options.AdditionalDatasets = multiDatasetOptions.AdditionalDatasets.ToList();
+            });
+
         builder.Services.AddHostedService<ConsoleInteractiveService>(); // Runs the Input Loop
 
         var host = builder.Build();

samples/ZB.MOM.WW.CBDDC.Sample.Console/SampleDbContext.cs

@@ -11,6 +11,8 @@ public class SampleDbContext : IDisposable
 {
     private const string UsersTable = "sample_users";
     private const string TodoListsTable = "sample_todo_lists";
+    private const string LogsTable = "sample_logs";
+    private const string TimeseriesTable = "sample_timeseries";
 
     private readonly bool _ownsClient;
 
@@ -28,6 +30,8 @@ public class SampleDbContext : IDisposable
 
         Users = new SampleSurrealCollection<User>(UsersTable, u => u.Id, SurrealEmbeddedClient, SchemaInitializer);
         TodoLists = new SampleSurrealCollection<TodoList>(TodoListsTable, t => t.Id, SurrealEmbeddedClient, SchemaInitializer);
+        Logs = new SampleSurrealCollection<TelemetryLogEntry>(LogsTable, e => e.Id, SurrealEmbeddedClient, SchemaInitializer);
+        Timeseries = new SampleSurrealCollection<TimeseriesPoint>(TimeseriesTable, p => p.Id, SurrealEmbeddedClient, SchemaInitializer);
         OplogEntries = new SampleSurrealReadOnlyCollection<SampleOplogEntry>(
             CBDDCSurrealSchemaNames.OplogEntriesTable,
             SurrealEmbeddedClient,
@@ -57,6 +61,8 @@ public class SampleDbContext : IDisposable
 
         Users = new SampleSurrealCollection<User>(UsersTable, u => u.Id, SurrealEmbeddedClient, SchemaInitializer);
         TodoLists = new SampleSurrealCollection<TodoList>(TodoListsTable, t => t.Id, SurrealEmbeddedClient, SchemaInitializer);
+        Logs = new SampleSurrealCollection<TelemetryLogEntry>(LogsTable, e => e.Id, SurrealEmbeddedClient, SchemaInitializer);
+        Timeseries = new SampleSurrealCollection<TimeseriesPoint>(TimeseriesTable, p => p.Id, SurrealEmbeddedClient, SchemaInitializer);
         OplogEntries = new SampleSurrealReadOnlyCollection<SampleOplogEntry>(
             CBDDCSurrealSchemaNames.OplogEntriesTable,
             SurrealEmbeddedClient,
@@ -88,6 +94,16 @@ public class SampleDbContext : IDisposable
     /// </summary>
     public SampleSurrealReadOnlyCollection<SampleOplogEntry> OplogEntries { get; private set; }
 
+    /// <summary>
+    /// Gets the append-only telemetry logs collection.
+    /// </summary>
+    public SampleSurrealCollection<TelemetryLogEntry> Logs { get; private set; }
+
+    /// <summary>
+    /// Gets the append-only timeseries collection.
+    /// </summary>
+    public SampleSurrealCollection<TimeseriesPoint> Timeseries { get; private set; }
+
     /// <summary>
     /// Ensures schema changes are applied before persisting updates.
     /// </summary>
@@ -102,6 +118,8 @@ public class SampleDbContext : IDisposable
     {
         Users.Dispose();
         TodoLists.Dispose();
+        Logs.Dispose();
+        Timeseries.Dispose();
 
         if (_ownsClient) SurrealEmbeddedClient.Dispose();
     }
@@ -126,6 +144,8 @@ public sealed class SampleSurrealSchemaInitializer : ICBDDCSurrealSchemaInitiali
     private const string SampleSchemaSql = """
                                            DEFINE TABLE OVERWRITE sample_users SCHEMALESS CHANGEFEED 7d;
                                            DEFINE TABLE OVERWRITE sample_todo_lists SCHEMALESS CHANGEFEED 7d;
+                                           DEFINE TABLE OVERWRITE sample_logs SCHEMALESS CHANGEFEED 7d;
+                                           DEFINE TABLE OVERWRITE sample_timeseries SCHEMALESS CHANGEFEED 7d;
                                            """;
     private readonly ICBDDCSurrealEmbeddedClient _client;
     private int _initialized;

samples/ZB.MOM.WW.CBDDC.Sample.Console/SampleDocumentStore.cs

@@ -14,6 +14,8 @@ public class SampleDocumentStore : SurrealDocumentStore<SampleDbContext>
 {
     private const string UsersCollection = "Users";
     private const string TodoListsCollection = "TodoLists";
+    private const string LogsCollection = "Logs";
+    private const string TimeseriesCollection = "Timeseries";
 
     /// <summary>
     ///     Initializes a new instance of the <see cref="SampleDocumentStore"/> class.
@@ -40,6 +42,8 @@ public class SampleDocumentStore : SurrealDocumentStore<SampleDbContext>
     {
         WatchCollection(UsersCollection, context.Users, u => u.Id);
         WatchCollection(TodoListsCollection, context.TodoLists, t => t.Id);
+        WatchCollection(LogsCollection, context.Logs, entry => entry.Id);
+        WatchCollection(TimeseriesCollection, context.Timeseries, point => point.Id);
     }
 
     /// <inheritdoc />
@@ -71,6 +75,8 @@ public class SampleDocumentStore : SurrealDocumentStore<SampleDbContext>
         {
             UsersCollection => SerializeEntity(await _context.Users.FindByIdAsync(key, cancellationToken)),
             TodoListsCollection => SerializeEntity(await _context.TodoLists.FindByIdAsync(key, cancellationToken)),
+            LogsCollection => SerializeEntity(await _context.Logs.FindByIdAsync(key, cancellationToken)),
+            TimeseriesCollection => SerializeEntity(await _context.Timeseries.FindByIdAsync(key, cancellationToken)),
             _ => null
         };
     }
@@ -106,6 +112,12 @@ public class SampleDocumentStore : SurrealDocumentStore<SampleDbContext>
             TodoListsCollection => (await _context.TodoLists.FindAllAsync(cancellationToken))
                 .Select(t => (t.Id, SerializeEntity(t)!.Value))
                 .ToList(),
+            LogsCollection => (await _context.Logs.FindAllAsync(cancellationToken))
+                .Select(entry => (entry.Id, SerializeEntity(entry)!.Value))
+                .ToList(),
+            TimeseriesCollection => (await _context.Timeseries.FindAllAsync(cancellationToken))
+                .Select(point => (point.Id, SerializeEntity(point)!.Value))
+                .ToList(),
             _ => []
         };
     }
@@ -137,6 +149,26 @@ public class SampleDocumentStore : SurrealDocumentStore<SampleDbContext>
                     await _context.TodoLists.UpdateAsync(todo, cancellationToken);
                 break;
 
+            case LogsCollection:
+                var logEntry = content.Deserialize<TelemetryLogEntry>() ??
+                               throw new InvalidOperationException("Failed to deserialize telemetry log.");
+                logEntry.Id = key;
+                if (await _context.Logs.FindByIdAsync(key, cancellationToken) == null)
+                    await _context.Logs.InsertAsync(logEntry, cancellationToken);
+                else
+                    await _context.Logs.UpdateAsync(logEntry, cancellationToken);
+                break;
+
+            case TimeseriesCollection:
+                var point = content.Deserialize<TimeseriesPoint>() ??
+                            throw new InvalidOperationException("Failed to deserialize timeseries point.");
+                point.Id = key;
+                if (await _context.Timeseries.FindByIdAsync(key, cancellationToken) == null)
+                    await _context.Timeseries.InsertAsync(point, cancellationToken);
+                else
+                    await _context.Timeseries.UpdateAsync(point, cancellationToken);
+                break;
+
             default:
                 throw new NotSupportedException($"Collection '{collection}' is not supported for sync.");
         }
@@ -152,6 +184,12 @@ public class SampleDocumentStore : SurrealDocumentStore<SampleDbContext>
             case TodoListsCollection:
                 await _context.TodoLists.DeleteAsync(key, cancellationToken);
                 break;
+            case LogsCollection:
+                await _context.Logs.DeleteAsync(key, cancellationToken);
+                break;
+            case TimeseriesCollection:
+                await _context.Timeseries.DeleteAsync(key, cancellationToken);
+                break;
             default:
                 _logger.LogWarning("Attempted to remove entity from unsupported collection: {Collection}", collection);
                 break;

samples/ZB.MOM.WW.CBDDC.Sample.Console/TelemetryData.cs

@@ -0,0 +1,57 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace ZB.MOM.WW.CBDDC.Sample.Console;
+
+/// <summary>
+///     Append-only telemetry log entry used for high-volume sync scenarios.
+/// </summary>
+public class TelemetryLogEntry
+{
+    /// <summary>
+    ///     Gets or sets the unique log identifier.
+    /// </summary>
+    [Key]
+    public string Id { get; set; } = Guid.NewGuid().ToString("N");
+
+    /// <summary>
+    ///     Gets or sets the log level.
+    /// </summary>
+    public string Level { get; set; } = "Information";
+
+    /// <summary>
+    ///     Gets or sets the log message.
+    /// </summary>
+    public string Message { get; set; } = string.Empty;
+
+    /// <summary>
+    ///     Gets or sets the UTC timestamp.
+    /// </summary>
+    public DateTime CreatedUtc { get; set; } = DateTime.UtcNow;
+}
+
+/// <summary>
+///     Append-only timeseries metric point used for telemetry sync scenarios.
+/// </summary>
+public class TimeseriesPoint
+{
+    /// <summary>
+    ///     Gets or sets the unique metric point identifier.
+    /// </summary>
+    [Key]
+    public string Id { get; set; } = Guid.NewGuid().ToString("N");
+
+    /// <summary>
+    ///     Gets or sets the metric name.
+    /// </summary>
+    public string Metric { get; set; } = "cpu";
+
+    /// <summary>
+    ///     Gets or sets the metric value.
+    /// </summary>
+    public double Value { get; set; }
+
+    /// <summary>
+    ///     Gets or sets the UTC timestamp.
+    /// </summary>
+    public DateTime RecordedUtc { get; set; } = DateTime.UtcNow;
+}

samples/ZB.MOM.WW.CBDDC.Sample.Console/appsettings.json

@@ -34,6 +34,12 @@
       "EnableOfflineQueue": true,
       "MaxQueueSize": 1000
     },
+    "MultiDataset": {
+      "EnableMultiDatasetSync": true,
+      "EnableDatasetPrimary": true,
+      "EnableDatasetLogs": true,
+      "EnableDatasetTimeseries": true
+    },
     "Logging": {
       "LogLevel": "Information",
       "LogFilePath": "logs/cbddc.log",

separate.md

@@ -0,0 +1,323 @@
+# In-Process Multi-Dataset Sync Plan (Worktree Execution)
+
+## Goal
+
+Add true in-process multi-dataset sync so primary business data can sync independently from high-volume append-only datasets (logs, timeseries), with separate state, scheduling, and backpressure behavior.
+
+## Desired Outcome
+
+1. Primary dataset sync throughput/latency is not materially impacted by telemetry dataset volume.
+2. Log and timeseries datasets use independent sync pipelines in the same process.
+3. Existing single-dataset apps continue to work with minimal/no code changes.
+4. Test coverage explicitly verifies isolation and no cross-dataset leakage.
+
+## Current Baseline (Why This Change Is Needed)
+
+1. Current host wiring registers a single `IDocumentStore`, `IOplogStore`, and `ISyncOrchestrator` graph.
+2. Collection filtering exists, but all collections still share one orchestrator/sync loop and one oplog/vector clock lifecycle.
+3. Protocol filters by collection only; there is no dataset identity boundary.
+4. Surreal schema objects are fixed names per configured namespace/database and are not dataset-aware by design.
+
+## Proposed Target Architecture
+
+## New Concepts
+
+1. `DatasetId`:
+   - Stable identifier (`primary`, `logs`, `timeseries`, etc).
+   - Included in all sync-state-bearing entities and wire messages.
+2. `DatasetSyncContext`:
+   - Encapsulates one dataset's services: document store adapter, oplog store, snapshot metadata, peer confirmation state, orchestrator configuration.
+3. `IMultiDatasetSyncOrchestrator`:
+   - Host-level coordinator that starts/stops one `ISyncOrchestrator` per dataset.
+4. `DatasetSyncOptions`:
+   - Per-dataset scheduling and limits (loop delay, max peers, optional bandwidth/entry caps, maintenance interval override).
+
+## Isolation Model
+
+1. Independent per-dataset oplog stream and vector clock.
+2. Independent per-dataset peer confirmation watermarks for pruning.
+3. Independent per-dataset transport filtering (handshake and pull/push include dataset id).
+4. Independent per-dataset observability counters.
+
+## Compatibility Strategy
+
+1. Backward compatible wire changes:
+   - Add optional `dataset_id` fields; default to `"primary"` when absent.
+2. Backward compatible storage:
+   - Add `datasetId` columns/fields where needed.
+   - Existing rows default to `"primary"` during migration/read fallback.
+3. API defaults:
+   - Existing single-store registration maps to dataset `"primary"` with no functional change.
+
+## Git Worktree Execution Plan
+
+## 0. Worktree Preparation
+
+1. Create worktree and branch:
+   - `git worktree add ../CBDDC-multidataset -b codex/multidataset-sync`
+2. Build baseline in worktree:
+   - `dotnet build CBDDC.slnx`
+3. Capture baseline tests (save output artifact in worktree):
+   - `dotnet test CBDDC.slnx`
+
+Deliverable:
+1. Clean baseline build/test result captured before changes.
+
+## 1. Design and Contract Layer
+
+### Code Changes
+
+1. Add dataset contracts in `src/ZB.MOM.WW.CBDDC.Core`:
+   - `DatasetId` value object or constants.
+   - `DatasetSyncOptions`.
+   - `IDatasetSyncContext`/`IMultiDatasetSyncOrchestrator`.
+2. Extend domain models where sync identity is required:
+   - `OplogEntry` add `DatasetId` (constructor defaults to `"primary"`).
+   - Any metadata types used for causal state/pruning that need dataset partitioning.
+3. Extend store interfaces (minimally invasive):
+   - Keep existing methods as compatibility overloads.
+   - Add dataset-aware variants where cross-dataset ambiguity exists.
+
+### Test Work
+
+1. Add Core unit tests:
+   - `OplogEntry` hash stability with `DatasetId`.
+   - Defaulting behavior to `"primary"`.
+   - Equality/serialization behavior for dataset-aware records.
+2. Update existing Core tests that construct `OplogEntry` directly.
+
+Exit Criteria:
+1. Core tests compile and pass with default dataset behavior unchanged.
+
+## 2. Persistence Partitioning (Surreal)
+
+### Code Changes
+
+1. Add dataset partition key to persistence records:
+   - Oplog rows.
+   - Document metadata rows.
+   - Snapshot metadata rows (if used in dataset-scoped recoveries).
+   - Peer confirmation records.
+   - CDC checkpoints (consumer id should include dataset id or add dedicated field).
+2. Update schema initializer:
+   - Add `datasetId` fields and composite indexes (`datasetId + existing key dimensions`).
+3. Update queries in all Surreal stores:
+   - Enforce dataset filter in every select/update/delete path.
+   - Guard against full-table scans that omit dataset filter.
+4. Add migration/read fallback:
+   - If `datasetId` missing on older records, treat as `"primary"` during transitional reads.
+
+### Test Work
+
+1. Extend `SurrealStoreContractTests`:
+   - Write records in two datasets and verify strict isolation.
+   - Verify prune/merge/export/import scoped by dataset.
+2. Add regression tests:
+   - Legacy records without `datasetId` load as `"primary"` only.
+3. Update durability tests:
+   - CDC checkpoints do not collide between datasets.
+
+Exit Criteria:
+1. Persistence tests prove no cross-dataset reads/writes.
+
+## 3. Network Protocol Dataset Awareness
+
+### Code Changes
+
+1. Update `sync.proto` (backward compatible):
+   - Add `dataset_id` to `HandshakeRequest`, `HandshakeResponse`, `PullChangesRequest`, `PushChangesRequest`, and optionally snapshot requests.
+2. Regenerate protocol classes and adapt transport handlers:
+   - `TcpPeerClient` sends dataset id for every dataset pipeline.
+   - `TcpSyncServer` routes requests to correct dataset context.
+3. Defaulting rules:
+   - Missing/empty `dataset_id` => `"primary"`.
+4. Add explicit rejection semantics:
+   - If remote peer does not support requested dataset, return accepted handshake but with dataset capability mismatch response path (or reject per dataset connection).
+
+### Test Work
+
+1. Add protocol-level unit tests:
+   - Message parse/serialize with and without dataset field.
+2. Update network tests:
+   - Handshake stores remote interests per dataset.
+   - Pull/push operations do not cross datasets.
+   - Backward compatibility with no dataset id present.
+
+Exit Criteria:
+1. Network tests pass for both new and legacy message shapes.
+
+## 4. Multi-Orchestrator Runtime and DI
+
+### Code Changes
+
+1. Add multi-dataset DI registration extensions:
+   - `AddCBDDCSurrealEmbeddedDataset(...)`
+   - `AddCBDDCMultiDataset(...)`
+2. Build `MultiDatasetSyncOrchestrator`:
+   - Start/stop orchestrators for configured datasets.
+   - Isolated cancellation tokens, loops, and failure handling per dataset.
+3. Ensure hosting services (`CBDDCNodeService`, `TcpSyncServerHostedService`) initialize dataset contexts deterministically.
+4. Add per-dataset knobs:
+   - Sync interval, max entries per cycle, maintenance interval, optional parallelism limits.
+
+### Test Work
+
+1. Add Hosting tests:
+   - Multiple datasets register/start/stop cleanly.
+   - Failure in one dataset does not stop others.
+2. Add orchestrator tests:
+   - Scheduling fairness and per-dataset failure backoff isolation.
+3. Update `NoOp`/fallback tests for multi-dataset mode.
+
+Exit Criteria:
+1. Runtime starts N dataset pipelines with independent lifecycle behavior.
+
+## 5. Snapshot and Recovery Semantics
+
+### Code Changes
+
+1. Define snapshot scope options:
+   - Per-dataset snapshot and full multi-dataset snapshot.
+2. Update snapshot service APIs and implementations to support:
+   - Export/import/merge by dataset id.
+3. Ensure emergency recovery paths in orchestrator are dataset-scoped.
+
+### Test Work
+
+1. Add snapshot tests:
+   - Replace/merge for one dataset leaves others untouched.
+2. Update reconnect regression tests:
+   - Snapshot-required flow only affects targeted dataset pipeline.
+
+Exit Criteria:
+1. Recovery operations preserve dataset isolation.
+
+## 6. Sample App and Developer Experience
+
+### Code Changes
+
+1. Add sample configuration for three datasets:
+   - `primary`, `logs`, `timeseries`.
+2. Implement append-only sample stores for `logs` and `timeseries`.
+3. Expose sample CLI commands to emit load independently per dataset.
+
+### Test Work
+
+1. Add sample integration tests:
+   - Heavy append load on logs/timeseries does not significantly delay primary data convergence.
+2. Add benchmark harness cases:
+   - Single-dataset baseline vs multi-dataset under telemetry load.
+
+Exit Criteria:
+1. Demonstrable isolation in sample workload.
+
+## 7. Documentation and Migration Guides
+
+### Code/Docs Changes
+
+1. New doc: `docs/features/multi-dataset-sync.md`.
+2. Update:
+   - `docs/architecture.md`
+   - `docs/persistence-providers.md`
+   - `docs/runbook.md`
+3. Add migration notes:
+   - From single pipeline to multi-dataset configuration.
+   - Backward compatibility and rollout toggles.
+
+### Test Work
+
+1. Doc examples compile check (if applicable).
+2. Add config parsing tests for dataset option sections.
+
+Exit Criteria:
+1. Operators have explicit rollout and rollback steps.
+
+## 8. Rollout Strategy (Safe Adoption)
+
+1. Feature flags:
+   - `EnableMultiDatasetSync` (global).
+   - `EnableDatasetPrimary/Logs/Timeseries`.
+2. Rollout sequence:
+   - Stage 1: Deploy with flag off.
+   - Stage 2: Enable `primary` only in new runtime path.
+   - Stage 3: Enable `logs`, then `timeseries`.
+3. Observability gates:
+   - Primary sync latency SLO must remain within threshold before enabling telemetry datasets.
+
+## 9. Test Plan (Comprehensive Coverage Matrix)
+
+## Unit Tests
+
+1. Core model defaults and hash behavior with dataset id.
+2. Dataset routing logic in orchestrator dispatcher.
+3. Protocol adapters default `dataset_id` to `"primary"` when absent.
+4. Persistence query builders always include dataset predicate.
+
+## Integration Tests
+
+1. Surreal stores:
+   - Same key/collection in different datasets remains isolated.
+2. Network:
+   - Pull/push with mixed datasets never cross-stream.
+3. Hosting:
+   - Independent orchestrator lifecycle and failure isolation.
+
+## E2E Tests
+
+1. Multi-node cluster:
+   - Primary converges under heavy append-only telemetry load.
+2. Snapshot/recovery:
+   - Dataset-scoped restore preserves other datasets.
+3. Backward compatibility:
+   - Legacy node (no dataset id) interoperates on `"primary"`.
+
+## Non-Functional Tests
+
+1. Throughput and latency benchmarks:
+   - Compare primary p95 sync lag before/after.
+2. Resource isolation:
+   - CPU/memory pressure from telemetry datasets should not break primary SLO.
+
+## Test Update Checklist (Existing Tests to Modify)
+
+1. `tests/ZB.MOM.WW.CBDDC.Core.Tests`:
+   - Update direct `OplogEntry` constructions.
+2. `tests/ZB.MOM.WW.CBDDC.Network.Tests`:
+   - Handshake/connection/vector-clock tests for dataset-aware flows.
+3. `tests/ZB.MOM.WW.CBDDC.Hosting.Tests`:
+   - Add multi-dataset startup/shutdown/failure cases.
+4. `tests/ZB.MOM.WW.CBDDC.Sample.Console.Tests`:
+   - Extend Surreal contract and durability tests for dataset partitioning.
+5. `tests/ZB.MOM.WW.CBDDC.E2E.Tests`:
+   - Add multi-dataset convergence + interference tests.
+
+## Worktree Task Breakdown (Execution Order)
+
+1. `Phase-A`: Contracts + Core model updates + unit tests.
+2. `Phase-B`: Surreal schema/store partitioning + persistence tests.
+3. `Phase-C`: Protocol and network routing + network tests.
+4. `Phase-D`: Multi-orchestrator DI/runtime + hosting tests.
+5. `Phase-E`: Snapshot/recovery updates + regression tests.
+6. `Phase-F`: Sample/bench/docs + end-to-end verification.
+
+Each phase should be committed separately in the worktree to keep reviewable deltas.
+
+## Validation Commands (Run in Worktree)
+
+1. `dotnet build /Users/dohertj2/Desktop/CBDDC/CBDDC.slnx`
+2. `dotnet test /Users/dohertj2/Desktop/CBDDC/CBDDC.slnx`
+3. Focused suites during implementation:
+   - `dotnet test /Users/dohertj2/Desktop/CBDDC/tests/ZB.MOM.WW.CBDDC.Core.Tests/ZB.MOM.WW.CBDDC.Core.Tests.csproj`
+   - `dotnet test /Users/dohertj2/Desktop/CBDDC/tests/ZB.MOM.WW.CBDDC.Network.Tests/ZB.MOM.WW.CBDDC.Network.Tests.csproj`
+   - `dotnet test /Users/dohertj2/Desktop/CBDDC/tests/ZB.MOM.WW.CBDDC.Hosting.Tests/ZB.MOM.WW.CBDDC.Hosting.Tests.csproj`
+   - `dotnet test /Users/dohertj2/Desktop/CBDDC/tests/ZB.MOM.WW.CBDDC.Sample.Console.Tests/ZB.MOM.WW.CBDDC.Sample.Console.Tests.csproj`
+   - `dotnet test /Users/dohertj2/Desktop/CBDDC/tests/ZB.MOM.WW.CBDDC.E2E.Tests/ZB.MOM.WW.CBDDC.E2E.Tests.csproj`
+
+## Definition of Done
+
+1. Multi-dataset mode runs `primary`, `logs`, and `timeseries` in one process with independent sync paths.
+2. No cross-dataset data movement in persistence, protocol, or runtime.
+3. Single-dataset existing usage still works via default `"primary"` dataset.
+4. Added/updated unit, integration, and E2E tests pass in CI.
+5. Docs include migration and operational guidance.
+

src/ZB.MOM.WW.CBDDC.Core/DatasetId.cs

@@ -0,0 +1,34 @@
+namespace ZB.MOM.WW.CBDDC.Core;
+
+/// <summary>
+///     Provides well-known dataset identifiers and normalization helpers.
+/// </summary>
+public static class DatasetId
+{
+    /// <summary>
+    ///     The default dataset identifier used by legacy single-dataset deployments.
+    /// </summary>
+    public const string Primary = "primary";
+
+    /// <summary>
+    ///     A high-volume append-only telemetry/log dataset identifier.
+    /// </summary>
+    public const string Logs = "logs";
+
+    /// <summary>
+    ///     A high-volume append-only timeseries dataset identifier.
+    /// </summary>
+    public const string Timeseries = "timeseries";
+
+    /// <summary>
+    ///     Normalizes a dataset identifier and applies the default when missing.
+    /// </summary>
+    /// <param name="datasetId">The raw dataset identifier.</param>
+    /// <returns>The normalized dataset identifier.</returns>
+    public static string Normalize(string? datasetId)
+    {
+        return string.IsNullOrWhiteSpace(datasetId)
+            ? Primary
+            : datasetId.Trim().ToLowerInvariant();
+    }
+}

src/ZB.MOM.WW.CBDDC.Core/DatasetSyncOptions.cs

@@ -0,0 +1,45 @@
+using System;
+using System.Collections.Generic;
+
+namespace ZB.MOM.WW.CBDDC.Core;
+
+/// <summary>
+///     Configures synchronization behavior for a single dataset pipeline.
+/// </summary>
+public sealed class DatasetSyncOptions
+{
+    /// <summary>
+    ///     Gets or sets the dataset identifier.
+    /// </summary>
+    public string DatasetId { get; set; } = global::ZB.MOM.WW.CBDDC.Core.DatasetId.Primary;
+
+    /// <summary>
+    ///     Gets or sets a value indicating whether this dataset pipeline is enabled.
+    /// </summary>
+    public bool Enabled { get; set; } = true;
+
+    /// <summary>
+    ///     Gets or sets the delay between sync loop cycles.
+    /// </summary>
+    public TimeSpan SyncLoopDelay { get; set; } = TimeSpan.FromSeconds(2);
+
+    /// <summary>
+    ///     Gets or sets the maximum number of peers selected per cycle.
+    /// </summary>
+    public int MaxPeersPerCycle { get; set; } = 3;
+
+    /// <summary>
+    ///     Gets or sets the maximum number of oplog entries pushed or pulled in one cycle.
+    /// </summary>
+    public int? MaxEntriesPerCycle { get; set; }
+
+    /// <summary>
+    ///     Gets or sets an optional maintenance interval override for this dataset.
+    /// </summary>
+    public TimeSpan? MaintenanceIntervalOverride { get; set; }
+
+    /// <summary>
+    ///     Gets or sets collection interests for this dataset pipeline.
+    /// </summary>
+    public List<string> InterestingCollections { get; set; } = [];
+}

src/ZB.MOM.WW.CBDDC.Core/OplogEntry.cs

@@ -24,6 +24,8 @@ public static class OplogEntryExtensions
         using var sha256 = SHA256.Create();
         var sb = new StringBuilder();
 
+        sb.Append(DatasetId.Normalize(entry.DatasetId));
+        sb.Append('|');
         sb.Append(entry.Collection);
         sb.Append('|');
         sb.Append(entry.Key);
@@ -59,9 +61,11 @@ public class OplogEntry
     /// <param name="timestamp">The logical timestamp.</param>
     /// <param name="previousHash">The previous entry hash.</param>
     /// <param name="hash">The current entry hash. If null, it is computed.</param>
+    /// <param name="datasetId">The dataset identifier for this entry. Defaults to <c>primary</c>.</param>
     public OplogEntry(string collection, string key, OperationType operation, JsonElement? payload,
-        HlcTimestamp timestamp, string previousHash, string? hash = null)
+        HlcTimestamp timestamp, string previousHash, string? hash = null, string? datasetId = null)
     {
+        DatasetId = global::ZB.MOM.WW.CBDDC.Core.DatasetId.Normalize(datasetId);
         Collection = collection;
         Key = key;
         Operation = operation;
@@ -71,6 +75,11 @@ public class OplogEntry
         Hash = hash ?? this.ComputeHash();
     }
 
+    /// <summary>
+    ///     Gets the dataset identifier associated with this entry.
+    /// </summary>
+    public string DatasetId { get; }
+
     /// <summary>
     ///     Gets the collection name associated with this entry.
     /// </summary>

src/ZB.MOM.WW.CBDDC.Core/PeerOplogConfirmation.cs

@@ -7,6 +7,11 @@ namespace ZB.MOM.WW.CBDDC.Core;
 /// </summary>
 public class PeerOplogConfirmation
 {
+    /// <summary>
+    ///     Gets or sets the dataset identifier associated with this confirmation record.
+    /// </summary>
+    public string DatasetId { get; set; } = global::ZB.MOM.WW.CBDDC.Core.DatasetId.Primary;
+
     /// <summary>
     ///     Gets or sets the tracked peer node identifier.
     /// </summary>

src/ZB.MOM.WW.CBDDC.Core/SnapshotMetadata.cs

@@ -2,6 +2,11 @@ namespace ZB.MOM.WW.CBDDC.Core;
 
 public class SnapshotMetadata
 {
+    /// <summary>
+    ///     Gets or sets the dataset identifier associated with the snapshot metadata.
+    /// </summary>
+    public string DatasetId { get; set; } = global::ZB.MOM.WW.CBDDC.Core.DatasetId.Primary;
+
     /// <summary>
     ///     Gets or sets the node identifier associated with the snapshot.
     /// </summary>

src/ZB.MOM.WW.CBDDC.Core/Storage/IDatasetSyncContext.cs

@@ -0,0 +1,42 @@
+namespace ZB.MOM.WW.CBDDC.Core.Storage;
+
+/// <summary>
+///     Represents the storage and runtime contracts bound to a specific dataset pipeline.
+/// </summary>
+public interface IDatasetSyncContext
+{
+    /// <summary>
+    ///     Gets the dataset identifier represented by this context.
+    /// </summary>
+    string DatasetId { get; }
+
+    /// <summary>
+    ///     Gets the per-dataset synchronization options.
+    /// </summary>
+    DatasetSyncOptions Options { get; }
+
+    /// <summary>
+    ///     Gets the dataset-scoped document store.
+    /// </summary>
+    IDocumentStore DocumentStore { get; }
+
+    /// <summary>
+    ///     Gets the dataset-scoped oplog store.
+    /// </summary>
+    IOplogStore OplogStore { get; }
+
+    /// <summary>
+    ///     Gets the dataset-scoped snapshot metadata store.
+    /// </summary>
+    ISnapshotMetadataStore SnapshotMetadataStore { get; }
+
+    /// <summary>
+    ///     Gets the dataset-scoped snapshot service.
+    /// </summary>
+    ISnapshotService SnapshotService { get; }
+
+    /// <summary>
+    ///     Gets the optional dataset-scoped peer confirmation store.
+    /// </summary>
+    IPeerOplogConfirmationStore? PeerOplogConfirmationStore { get; }
+}

src/ZB.MOM.WW.CBDDC.Core/Storage/IDocumentMetadataStore.cs

@@ -20,6 +20,23 @@ public interface IDocumentMetadataStore : ISnapshotable<DocumentMetadata>
     Task<DocumentMetadata?> GetMetadataAsync(string collection, string key,
         CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Gets metadata for a specific document within a dataset.
+    /// </summary>
+    /// <param name="collection">The collection name.</param>
+    /// <param name="key">The document key.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>The matching metadata when found.</returns>
+    Task<DocumentMetadata?> GetMetadataAsync(
+        string collection,
+        string key,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return GetMetadataAsync(collection, key, cancellationToken);
+    }
+
     /// <summary>
     ///     Gets metadata for all documents in a collection.
     /// </summary>
@@ -29,6 +46,21 @@ public interface IDocumentMetadataStore : ISnapshotable<DocumentMetadata>
     Task<IEnumerable<DocumentMetadata>> GetMetadataByCollectionAsync(string collection,
         CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Gets metadata for all documents in a collection for the specified dataset.
+    /// </summary>
+    /// <param name="collection">The collection name.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>Enumerable of metadata rows.</returns>
+    Task<IEnumerable<DocumentMetadata>> GetMetadataByCollectionAsync(
+        string collection,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return GetMetadataByCollectionAsync(collection, cancellationToken);
+    }
+
     /// <summary>
     ///     Upserts (inserts or updates) metadata for a document.
     /// </summary>
@@ -36,6 +68,20 @@ public interface IDocumentMetadataStore : ISnapshotable<DocumentMetadata>
     /// <param name="cancellationToken">A cancellation token.</param>
     Task UpsertMetadataAsync(DocumentMetadata metadata, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Upserts metadata for a specific dataset.
+    /// </summary>
+    /// <param name="metadata">The metadata to upsert.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    Task UpsertMetadataAsync(
+        DocumentMetadata metadata,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return UpsertMetadataAsync(metadata, cancellationToken);
+    }
+
     /// <summary>
     ///     Upserts metadata for multiple documents in batch.
     /// </summary>
@@ -44,6 +90,20 @@ public interface IDocumentMetadataStore : ISnapshotable<DocumentMetadata>
     Task UpsertMetadataBatchAsync(IEnumerable<DocumentMetadata> metadatas,
         CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Upserts metadata batch for a specific dataset.
+    /// </summary>
+    /// <param name="metadatas">The metadata items.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    Task UpsertMetadataBatchAsync(
+        IEnumerable<DocumentMetadata> metadatas,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return UpsertMetadataBatchAsync(metadatas, cancellationToken);
+    }
+
     /// <summary>
     ///     Marks a document as deleted by setting IsDeleted=true and updating the timestamp.
     /// </summary>
@@ -54,6 +114,24 @@ public interface IDocumentMetadataStore : ISnapshotable<DocumentMetadata>
     Task MarkDeletedAsync(string collection, string key, HlcTimestamp timestamp,
         CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Marks a document as deleted in a specific dataset.
+    /// </summary>
+    /// <param name="collection">The collection name.</param>
+    /// <param name="key">The document key.</param>
+    /// <param name="timestamp">The deletion timestamp.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    Task MarkDeletedAsync(
+        string collection,
+        string key,
+        HlcTimestamp timestamp,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return MarkDeletedAsync(collection, key, timestamp, cancellationToken);
+    }
+
     /// <summary>
     ///     Gets all document metadata with timestamps after the specified timestamp.
     ///     Used for incremental sync to find documents modified since last sync.
@@ -64,6 +142,23 @@ public interface IDocumentMetadataStore : ISnapshotable<DocumentMetadata>
     /// <returns>Documents modified after the specified timestamp.</returns>
     Task<IEnumerable<DocumentMetadata>> GetMetadataAfterAsync(HlcTimestamp since,
         IEnumerable<string>? collections = null, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    ///     Gets document metadata modified after a timestamp for a specific dataset.
+    /// </summary>
+    /// <param name="since">The lower-bound timestamp.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="collections">Optional collection filter.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>Documents modified after the specified timestamp.</returns>
+    Task<IEnumerable<DocumentMetadata>> GetMetadataAfterAsync(
+        HlcTimestamp since,
+        string datasetId,
+        IEnumerable<string>? collections = null,
+        CancellationToken cancellationToken = default)
+    {
+        return GetMetadataAfterAsync(since, collections, cancellationToken);
+    }
 }
 
 /// <summary>
@@ -85,14 +180,22 @@ public class DocumentMetadata
     /// <param name="key">The document key.</param>
     /// <param name="updatedAt">The last update timestamp.</param>
     /// <param name="isDeleted">Whether the document is marked as deleted.</param>
-    public DocumentMetadata(string collection, string key, HlcTimestamp updatedAt, bool isDeleted = false)
+    /// <param name="datasetId">The dataset identifier. Defaults to <c>primary</c>.</param>
+    public DocumentMetadata(string collection, string key, HlcTimestamp updatedAt, bool isDeleted = false,
+        string? datasetId = null)
     {
         Collection = collection;
         Key = key;
         UpdatedAt = updatedAt;
         IsDeleted = isDeleted;
+        DatasetId = global::ZB.MOM.WW.CBDDC.Core.DatasetId.Normalize(datasetId);
     }
 
+    /// <summary>
+    ///     Gets or sets the dataset identifier.
+    /// </summary>
+    public string DatasetId { get; set; } = global::ZB.MOM.WW.CBDDC.Core.DatasetId.Primary;
+
     /// <summary>
     ///     Gets or sets the collection name.
     /// </summary>

src/ZB.MOM.WW.CBDDC.Core/Storage/IMultiDatasetSyncOrchestrator.cs

@@ -0,0 +1,25 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace ZB.MOM.WW.CBDDC.Core.Storage;
+
+/// <summary>
+///     Coordinates the lifecycle of multiple dataset synchronization pipelines.
+/// </summary>
+public interface IMultiDatasetSyncOrchestrator
+{
+    /// <summary>
+    ///     Gets the registered dataset contexts.
+    /// </summary>
+    IReadOnlyCollection<IDatasetSyncContext> Contexts { get; }
+
+    /// <summary>
+    ///     Starts synchronization for all configured datasets.
+    /// </summary>
+    Task Start();
+
+    /// <summary>
+    ///     Stops synchronization for all configured datasets.
+    /// </summary>
+    Task Stop();
+}

src/ZB.MOM.WW.CBDDC.Core/Storage/IOplogStore.cs

@@ -23,6 +23,21 @@ public interface IOplogStore : ISnapshotable<OplogEntry>
     /// <returns>A task that represents the asynchronous append operation.</returns>
     Task AppendOplogEntryAsync(OplogEntry entry, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Appends a new entry to the operation log asynchronously for a specific dataset.
+    /// </summary>
+    /// <param name="entry">The operation log entry to append.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task that represents the asynchronous append operation.</returns>
+    Task AppendOplogEntryAsync(
+        OplogEntry entry,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return AppendOplogEntryAsync(entry, cancellationToken);
+    }
+
     /// <summary>
     ///     Asynchronously retrieves all oplog entries that occurred after the specified timestamp.
     /// </summary>
@@ -33,6 +48,23 @@ public interface IOplogStore : ISnapshotable<OplogEntry>
     Task<IEnumerable<OplogEntry>> GetOplogAfterAsync(HlcTimestamp timestamp, IEnumerable<string>? collections = null,
         CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Asynchronously retrieves oplog entries after the specified timestamp for a specific dataset.
+    /// </summary>
+    /// <param name="timestamp">The lower-bound timestamp.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="collections">Optional collection filter.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task containing matching oplog entries.</returns>
+    Task<IEnumerable<OplogEntry>> GetOplogAfterAsync(
+        HlcTimestamp timestamp,
+        string datasetId,
+        IEnumerable<string>? collections = null,
+        CancellationToken cancellationToken = default)
+    {
+        return GetOplogAfterAsync(timestamp, collections, cancellationToken);
+    }
+
     /// <summary>
     ///     Asynchronously retrieves the latest observed hybrid logical clock (HLC) timestamp.
     /// </summary>
@@ -40,6 +72,17 @@ public interface IOplogStore : ISnapshotable<OplogEntry>
     /// <returns>A task that represents the asynchronous operation containing the latest HLC timestamp.</returns>
     Task<HlcTimestamp> GetLatestTimestampAsync(CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Asynchronously retrieves the latest observed timestamp for a specific dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task containing the latest timestamp.</returns>
+    Task<HlcTimestamp> GetLatestTimestampAsync(string datasetId, CancellationToken cancellationToken = default)
+    {
+        return GetLatestTimestampAsync(cancellationToken);
+    }
+
     /// <summary>
     ///     Asynchronously retrieves the current vector clock representing the state of distributed events.
     /// </summary>
@@ -47,6 +90,17 @@ public interface IOplogStore : ISnapshotable<OplogEntry>
     /// <returns>A task that represents the asynchronous operation containing the current vector clock.</returns>
     Task<VectorClock> GetVectorClockAsync(CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Asynchronously retrieves the vector clock for a specific dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task containing the vector clock.</returns>
+    Task<VectorClock> GetVectorClockAsync(string datasetId, CancellationToken cancellationToken = default)
+    {
+        return GetVectorClockAsync(cancellationToken);
+    }
+
     /// <summary>
     ///     Retrieves a collection of oplog entries for the specified node that occurred after the given timestamp.
     /// </summary>
@@ -58,6 +112,25 @@ public interface IOplogStore : ISnapshotable<OplogEntry>
     Task<IEnumerable<OplogEntry>> GetOplogForNodeAfterAsync(string nodeId, HlcTimestamp since,
         IEnumerable<string>? collections = null, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Retrieves oplog entries for the specified node and dataset after the provided timestamp.
+    /// </summary>
+    /// <param name="nodeId">The node identifier.</param>
+    /// <param name="since">The lower-bound timestamp.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="collections">Optional collection filter.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task containing matching oplog entries.</returns>
+    Task<IEnumerable<OplogEntry>> GetOplogForNodeAfterAsync(
+        string nodeId,
+        HlcTimestamp since,
+        string datasetId,
+        IEnumerable<string>? collections = null,
+        CancellationToken cancellationToken = default)
+    {
+        return GetOplogForNodeAfterAsync(nodeId, since, collections, cancellationToken);
+    }
+
     /// <summary>
     ///     Asynchronously retrieves the hash of the most recent entry for the specified node.
     /// </summary>
@@ -69,6 +142,18 @@ public interface IOplogStore : ISnapshotable<OplogEntry>
     /// <returns>A task that represents the asynchronous operation containing the hash string of the last entry or null.</returns>
     Task<string?> GetLastEntryHashAsync(string nodeId, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Asynchronously retrieves the last entry hash for a node within a specific dataset.
+    /// </summary>
+    /// <param name="nodeId">The node identifier.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task containing the last hash or null.</returns>
+    Task<string?> GetLastEntryHashAsync(string nodeId, string datasetId, CancellationToken cancellationToken = default)
+    {
+        return GetLastEntryHashAsync(nodeId, cancellationToken);
+    }
+
     /// <summary>
     ///     Asynchronously retrieves a sequence of oplog entries representing the chain between the specified start and end
     ///     hashes.
@@ -80,6 +165,23 @@ public interface IOplogStore : ISnapshotable<OplogEntry>
     Task<IEnumerable<OplogEntry>> GetChainRangeAsync(string startHash, string endHash,
         CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Asynchronously retrieves a chain range for a specific dataset.
+    /// </summary>
+    /// <param name="startHash">The start hash.</param>
+    /// <param name="endHash">The end hash.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task containing chain entries.</returns>
+    Task<IEnumerable<OplogEntry>> GetChainRangeAsync(
+        string startHash,
+        string endHash,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return GetChainRangeAsync(startHash, endHash, cancellationToken);
+    }
+
     /// <summary>
     ///     Asynchronously retrieves the oplog entry associated with the specified hash value.
     /// </summary>
@@ -88,6 +190,18 @@ public interface IOplogStore : ISnapshotable<OplogEntry>
     /// <returns>A task representing the asynchronous operation containing the OplogEntry if found, otherwise null.</returns>
     Task<OplogEntry?> GetEntryByHashAsync(string hash, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Asynchronously retrieves an entry by hash for a specific dataset.
+    /// </summary>
+    /// <param name="hash">The entry hash.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task containing the entry when found.</returns>
+    Task<OplogEntry?> GetEntryByHashAsync(string hash, string datasetId, CancellationToken cancellationToken = default)
+    {
+        return GetEntryByHashAsync(hash, cancellationToken);
+    }
+
     /// <summary>
     ///     Applies a batch of oplog entries asynchronously to the target data store.
     /// </summary>
@@ -96,6 +210,21 @@ public interface IOplogStore : ISnapshotable<OplogEntry>
     /// <returns>A task that represents the asynchronous batch apply operation.</returns>
     Task ApplyBatchAsync(IEnumerable<OplogEntry> oplogEntries, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Applies a batch of oplog entries asynchronously for a specific dataset.
+    /// </summary>
+    /// <param name="oplogEntries">The entries to apply.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task that represents the apply operation.</returns>
+    Task ApplyBatchAsync(
+        IEnumerable<OplogEntry> oplogEntries,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return ApplyBatchAsync(oplogEntries, cancellationToken);
+    }
+
     /// <summary>
     ///     Asynchronously removes entries from the oplog that are older than the specified cutoff timestamp.
     /// </summary>
@@ -103,4 +232,16 @@ public interface IOplogStore : ISnapshotable<OplogEntry>
     /// <param name="cancellationToken">A cancellation token that can be used to cancel the prune operation.</param>
     /// <returns>A task that represents the asynchronous prune operation.</returns>
     Task PruneOplogAsync(HlcTimestamp cutoff, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    ///     Asynchronously removes entries from the specified dataset oplog that are older than the cutoff.
+    /// </summary>
+    /// <param name="cutoff">The prune cutoff timestamp.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task that represents the prune operation.</returns>
+    Task PruneOplogAsync(HlcTimestamp cutoff, string datasetId, CancellationToken cancellationToken = default)
+    {
+        return PruneOplogAsync(cutoff, cancellationToken);
+    }
 }

src/ZB.MOM.WW.CBDDC.Core/Storage/IPeerOplogConfirmationStore.cs

@@ -23,6 +23,24 @@ public interface IPeerOplogConfirmationStore : ISnapshotable<PeerOplogConfirmati
         PeerType type,
         CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Ensures the specified peer is tracked for a given dataset.
+    /// </summary>
+    /// <param name="peerNodeId">The peer node identifier.</param>
+    /// <param name="address">The peer address.</param>
+    /// <param name="type">The peer type.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    Task EnsurePeerRegisteredAsync(
+        string peerNodeId,
+        string address,
+        PeerType type,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return EnsurePeerRegisteredAsync(peerNodeId, address, type, cancellationToken);
+    }
+
     /// <summary>
     ///     Updates the confirmation watermark for a tracked peer and source node.
     /// </summary>
@@ -38,6 +56,26 @@ public interface IPeerOplogConfirmationStore : ISnapshotable<PeerOplogConfirmati
         string hash,
         CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Updates the confirmation watermark for a tracked peer and dataset.
+    /// </summary>
+    /// <param name="peerNodeId">The tracked peer node identifier.</param>
+    /// <param name="sourceNodeId">The source node identifier.</param>
+    /// <param name="timestamp">The confirmed timestamp.</param>
+    /// <param name="hash">The confirmed hash.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    Task UpdateConfirmationAsync(
+        string peerNodeId,
+        string sourceNodeId,
+        HlcTimestamp timestamp,
+        string hash,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return UpdateConfirmationAsync(peerNodeId, sourceNodeId, timestamp, hash, cancellationToken);
+    }
+
     /// <summary>
     ///     Gets all persisted peer confirmations.
     /// </summary>
@@ -45,6 +83,19 @@ public interface IPeerOplogConfirmationStore : ISnapshotable<PeerOplogConfirmati
     /// <returns>All peer confirmations.</returns>
     Task<IEnumerable<PeerOplogConfirmation>> GetConfirmationsAsync(CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Gets all persisted peer confirmations for a specific dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>All peer confirmations in the dataset.</returns>
+    Task<IEnumerable<PeerOplogConfirmation>> GetConfirmationsAsync(
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return GetConfirmationsAsync(cancellationToken);
+    }
+
     /// <summary>
     ///     Gets persisted confirmations for a specific tracked peer.
     /// </summary>
@@ -55,6 +106,21 @@ public interface IPeerOplogConfirmationStore : ISnapshotable<PeerOplogConfirmati
         string peerNodeId,
         CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Gets persisted confirmations for a specific peer and dataset.
+    /// </summary>
+    /// <param name="peerNodeId">The peer node identifier.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>Peer confirmations for the requested peer and dataset.</returns>
+    Task<IEnumerable<PeerOplogConfirmation>> GetConfirmationsForPeerAsync(
+        string peerNodeId,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return GetConfirmationsForPeerAsync(peerNodeId, cancellationToken);
+    }
+
     /// <summary>
     ///     Deactivates tracking for the specified peer.
     /// </summary>
@@ -62,10 +128,34 @@ public interface IPeerOplogConfirmationStore : ISnapshotable<PeerOplogConfirmati
     /// <param name="cancellationToken">A cancellation token.</param>
     Task RemovePeerTrackingAsync(string peerNodeId, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Deactivates tracking for a peer in a specific dataset.
+    /// </summary>
+    /// <param name="peerNodeId">The peer node identifier.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    Task RemovePeerTrackingAsync(string peerNodeId, string datasetId, CancellationToken cancellationToken = default)
+    {
+        return RemovePeerTrackingAsync(peerNodeId, cancellationToken);
+    }
+
     /// <summary>
     ///     Gets all active tracked peer identifiers.
     /// </summary>
     /// <param name="cancellationToken">A cancellation token.</param>
     /// <returns>Distinct active tracked peer identifiers.</returns>
     Task<IEnumerable<string>> GetActiveTrackedPeersAsync(CancellationToken cancellationToken = default);
+
+    /// <summary>
+    ///     Gets active tracked peers for a specific dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>Distinct active peer identifiers.</returns>
+    Task<IEnumerable<string>> GetActiveTrackedPeersAsync(
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return GetActiveTrackedPeersAsync(cancellationToken);
+    }
 }

src/ZB.MOM.WW.CBDDC.Core/Storage/ISnapshotMetadataStore.cs

@@ -20,6 +20,21 @@ public interface ISnapshotMetadataStore : ISnapshotable<SnapshotMetadata>
     /// </returns>
     Task<SnapshotMetadata?> GetSnapshotMetadataAsync(string nodeId, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Asynchronously retrieves snapshot metadata for a node within a specific dataset.
+    /// </summary>
+    /// <param name="nodeId">The node identifier.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>The snapshot metadata when available.</returns>
+    Task<SnapshotMetadata?> GetSnapshotMetadataAsync(
+        string nodeId,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return GetSnapshotMetadataAsync(nodeId, cancellationToken);
+    }
+
     /// <summary>
     ///     Asynchronously inserts the specified snapshot metadata into the data store.
     /// </summary>
@@ -28,6 +43,20 @@ public interface ISnapshotMetadataStore : ISnapshotable<SnapshotMetadata>
     /// <returns>A task that represents the asynchronous insert operation.</returns>
     Task InsertSnapshotMetadataAsync(SnapshotMetadata metadata, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Asynchronously inserts snapshot metadata for a specific dataset.
+    /// </summary>
+    /// <param name="metadata">The metadata to insert.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    Task InsertSnapshotMetadataAsync(
+        SnapshotMetadata metadata,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return InsertSnapshotMetadataAsync(metadata, cancellationToken);
+    }
+
     /// <summary>
     ///     Asynchronously updates the metadata for an existing snapshot.
     /// </summary>
@@ -36,6 +65,20 @@ public interface ISnapshotMetadataStore : ISnapshotable<SnapshotMetadata>
     /// <returns>A task that represents the asynchronous update operation.</returns>
     Task UpdateSnapshotMetadataAsync(SnapshotMetadata existingMeta, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Asynchronously updates snapshot metadata for a specific dataset.
+    /// </summary>
+    /// <param name="existingMeta">The metadata to update.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    Task UpdateSnapshotMetadataAsync(
+        SnapshotMetadata existingMeta,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return UpdateSnapshotMetadataAsync(existingMeta, cancellationToken);
+    }
+
     /// <summary>
     ///     Asynchronously retrieves the hash of the current snapshot for the specified node.
     /// </summary>
@@ -44,10 +87,38 @@ public interface ISnapshotMetadataStore : ISnapshotable<SnapshotMetadata>
     /// <returns>A task containing the snapshot hash as a string, or null if no snapshot is available.</returns>
     Task<string?> GetSnapshotHashAsync(string nodeId, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Asynchronously retrieves the snapshot hash for a node within a specific dataset.
+    /// </summary>
+    /// <param name="nodeId">The node identifier.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>The snapshot hash when available.</returns>
+    Task<string?> GetSnapshotHashAsync(
+        string nodeId,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return GetSnapshotHashAsync(nodeId, cancellationToken);
+    }
+
     /// <summary>
     ///     Gets all snapshot metadata entries. Used for initializing VectorClock cache.
     /// </summary>
     /// <param name="cancellationToken">A cancellation token.</param>
     /// <returns>All snapshot metadata entries.</returns>
     Task<IEnumerable<SnapshotMetadata>> GetAllSnapshotMetadataAsync(CancellationToken cancellationToken = default);
+
+    /// <summary>
+    ///     Gets all snapshot metadata entries for a specific dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>All snapshot metadata entries for the dataset.</returns>
+    Task<IEnumerable<SnapshotMetadata>> GetAllSnapshotMetadataAsync(
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return GetAllSnapshotMetadataAsync(cancellationToken);
+    }
 }

src/ZB.MOM.WW.CBDDC.Core/Storage/ISnapshotService.cs

@@ -17,6 +17,18 @@ public interface ISnapshotService
     /// <returns>A task that represents the asynchronous snapshot creation operation.</returns>
     Task CreateSnapshotAsync(Stream destination, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Asynchronously creates a snapshot scoped to a specific dataset and writes it to the destination stream.
+    /// </summary>
+    /// <param name="destination">The stream receiving serialized snapshot content.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task that represents the asynchronous snapshot creation operation.</returns>
+    Task CreateSnapshotAsync(Stream destination, string datasetId, CancellationToken cancellationToken = default)
+    {
+        return CreateSnapshotAsync(destination, cancellationToken);
+    }
+
     /// <summary>
     ///     Replaces the existing database with the contents provided in the specified stream asynchronously.
     /// </summary>
@@ -25,6 +37,18 @@ public interface ISnapshotService
     /// <returns>A task that represents the asynchronous database replacement operation.</returns>
     Task ReplaceDatabaseAsync(Stream databaseStream, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Replaces data for a specific dataset with the contents provided in the stream.
+    /// </summary>
+    /// <param name="databaseStream">The stream containing replacement data.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task that represents the asynchronous replace operation.</returns>
+    Task ReplaceDatabaseAsync(Stream databaseStream, string datasetId, CancellationToken cancellationToken = default)
+    {
+        return ReplaceDatabaseAsync(databaseStream, cancellationToken);
+    }
+
     /// <summary>
     ///     Merges the provided snapshot stream into the current data store asynchronously.
     /// </summary>
@@ -32,4 +56,16 @@ public interface ISnapshotService
     /// <param name="cancellationToken">A cancellation token that can be used to cancel the merge operation.</param>
     /// <returns>A task that represents the asynchronous merge operation.</returns>
     Task MergeSnapshotAsync(Stream snapshotStream, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    ///     Merges a snapshot stream into a specific dataset asynchronously.
+    /// </summary>
+    /// <param name="snapshotStream">The stream containing snapshot data.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task that represents the asynchronous merge operation.</returns>
+    Task MergeSnapshotAsync(Stream snapshotStream, string datasetId, CancellationToken cancellationToken = default)
+    {
+        return MergeSnapshotAsync(snapshotStream, cancellationToken);
+    }
 }

src/ZB.MOM.WW.CBDDC.Core/Storage/ISnapshotable.cs

@@ -17,6 +17,17 @@ public interface ISnapshotable<T>
     /// <returns>A task that represents the asynchronous drop operation.</returns>
     Task DropAsync(CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Asynchronously deletes data for the specified dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task that represents the asynchronous drop operation.</returns>
+    Task DropAsync(string datasetId, CancellationToken cancellationToken = default)
+    {
+        return DropAsync(cancellationToken);
+    }
+
     /// <summary>
     ///     Asynchronously exports a collection of items of type T.
     /// </summary>
@@ -27,6 +38,17 @@ public interface ISnapshotable<T>
     /// </returns>
     Task<IEnumerable<T>> ExportAsync(CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Asynchronously exports items for the specified dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>An enumerable collection of exported items.</returns>
+    Task<IEnumerable<T>> ExportAsync(string datasetId, CancellationToken cancellationToken = default)
+    {
+        return ExportAsync(cancellationToken);
+    }
+
     /// <summary>
     ///     Imports the specified collection of items asynchronously.
     /// </summary>
@@ -35,6 +57,18 @@ public interface ISnapshotable<T>
     /// <returns>A task that represents the asynchronous import operation.</returns>
     Task ImportAsync(IEnumerable<T> items, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Imports items into the specified dataset asynchronously.
+    /// </summary>
+    /// <param name="items">The items to import.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task that represents the asynchronous import operation.</returns>
+    Task ImportAsync(IEnumerable<T> items, string datasetId, CancellationToken cancellationToken = default)
+    {
+        return ImportAsync(items, cancellationToken);
+    }
+
     /// <summary>
     ///     Merges the specified collection of items into the target data store asynchronously.
     /// </summary>
@@ -47,4 +81,16 @@ public interface ISnapshotable<T>
     /// <param name="cancellationToken">A cancellation token that can be used to cancel the merge operation.</param>
     /// <returns>A task that represents the asynchronous merge operation.</returns>
     Task MergeAsync(IEnumerable<T> items, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    ///     Merges items into the specified dataset asynchronously.
+    /// </summary>
+    /// <param name="items">The items to merge.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A task that represents the asynchronous merge operation.</returns>
+    Task MergeAsync(IEnumerable<T> items, string datasetId, CancellationToken cancellationToken = default)
+    {
+        return MergeAsync(items, cancellationToken);
+    }
 }

src/ZB.MOM.WW.CBDDC.Network/DatasetSyncContext.cs

@@ -0,0 +1,67 @@
+using ZB.MOM.WW.CBDDC.Core;
+using ZB.MOM.WW.CBDDC.Core.Storage;
+
+namespace ZB.MOM.WW.CBDDC.Network;
+
+/// <summary>
+///     Default dataset sync context implementation used by the runtime coordinator.
+/// </summary>
+public sealed class DatasetSyncContext : IDatasetSyncContext
+{
+    /// <summary>
+    ///     Initializes a new instance of the <see cref="DatasetSyncContext" /> class.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="options">The dataset options.</param>
+    /// <param name="documentStore">The document store.</param>
+    /// <param name="oplogStore">The oplog store.</param>
+    /// <param name="snapshotMetadataStore">The snapshot metadata store.</param>
+    /// <param name="snapshotService">The snapshot service.</param>
+    /// <param name="peerOplogConfirmationStore">The optional peer confirmation store.</param>
+    /// <param name="orchestrator">The dataset orchestrator.</param>
+    public DatasetSyncContext(
+        string datasetId,
+        DatasetSyncOptions options,
+        IDocumentStore documentStore,
+        IOplogStore oplogStore,
+        ISnapshotMetadataStore snapshotMetadataStore,
+        ISnapshotService snapshotService,
+        IPeerOplogConfirmationStore? peerOplogConfirmationStore,
+        ISyncOrchestrator orchestrator)
+    {
+        DatasetId = global::ZB.MOM.WW.CBDDC.Core.DatasetId.Normalize(datasetId);
+        Options = options;
+        DocumentStore = documentStore;
+        OplogStore = oplogStore;
+        SnapshotMetadataStore = snapshotMetadataStore;
+        SnapshotService = snapshotService;
+        PeerOplogConfirmationStore = peerOplogConfirmationStore;
+        Orchestrator = orchestrator;
+    }
+
+    /// <inheritdoc />
+    public string DatasetId { get; }
+
+    /// <inheritdoc />
+    public DatasetSyncOptions Options { get; }
+
+    /// <inheritdoc />
+    public IDocumentStore DocumentStore { get; }
+
+    /// <inheritdoc />
+    public IOplogStore OplogStore { get; }
+
+    /// <inheritdoc />
+    public ISnapshotMetadataStore SnapshotMetadataStore { get; }
+
+    /// <inheritdoc />
+    public ISnapshotService SnapshotService { get; }
+
+    /// <inheritdoc />
+    public IPeerOplogConfirmationStore? PeerOplogConfirmationStore { get; }
+
+    /// <summary>
+    ///     Gets the orchestrator instance for this dataset context.
+    /// </summary>
+    public ISyncOrchestrator Orchestrator { get; }
+}

src/ZB.MOM.WW.CBDDC.Network/MultiDatasetRuntimeOptions.cs

@@ -0,0 +1,34 @@
+using ZB.MOM.WW.CBDDC.Core;
+
+namespace ZB.MOM.WW.CBDDC.Network;
+
+/// <summary>
+///     Feature flags and defaults for multi-dataset sync runtime activation.
+/// </summary>
+public sealed class MultiDatasetRuntimeOptions
+{
+    /// <summary>
+    ///     Gets or sets a value indicating whether multi-dataset sync runtime is enabled.
+    /// </summary>
+    public bool EnableMultiDatasetSync { get; set; }
+
+    /// <summary>
+    ///     Gets or sets a value indicating whether the primary dataset pipeline is enabled.
+    /// </summary>
+    public bool EnableDatasetPrimary { get; set; } = true;
+
+    /// <summary>
+    ///     Gets or sets a value indicating whether the logs dataset pipeline is enabled.
+    /// </summary>
+    public bool EnableDatasetLogs { get; set; }
+
+    /// <summary>
+    ///     Gets or sets a value indicating whether the timeseries dataset pipeline is enabled.
+    /// </summary>
+    public bool EnableDatasetTimeseries { get; set; }
+
+    /// <summary>
+    ///     Gets or sets additional dataset-specific runtime options.
+    /// </summary>
+    public List<DatasetSyncOptions> AdditionalDatasets { get; set; } = [];
+}

src/ZB.MOM.WW.CBDDC.Network/MultiDatasetSyncOrchestrator.cs

@@ -0,0 +1,199 @@
+using ZB.MOM.WW.CBDDC.Core;
+using ZB.MOM.WW.CBDDC.Core.Network;
+using ZB.MOM.WW.CBDDC.Core.Storage;
+using Microsoft.Extensions.Logging;
+using ZB.MOM.WW.CBDDC.Network.Security;
+using ZB.MOM.WW.CBDDC.Network.Telemetry;
+
+namespace ZB.MOM.WW.CBDDC.Network;
+
+/// <summary>
+///     Coordinates one sync orchestrator per dataset in-process.
+/// </summary>
+public sealed class MultiDatasetSyncOrchestrator : IMultiDatasetSyncOrchestrator
+{
+    private readonly ILoggerFactory _loggerFactory;
+    private readonly ILogger<MultiDatasetSyncOrchestrator> _logger;
+
+    /// <summary>
+    ///     Initializes a new instance of the <see cref="MultiDatasetSyncOrchestrator" /> class.
+    /// </summary>
+    /// <param name="discovery">The discovery service.</param>
+    /// <param name="oplogStore">The shared oplog store supporting dataset partitioning.</param>
+    /// <param name="documentStore">The document store.</param>
+    /// <param name="snapshotMetadataStore">The snapshot metadata store.</param>
+    /// <param name="snapshotService">The snapshot service.</param>
+    /// <param name="peerNodeConfigurationProvider">The peer configuration provider.</param>
+    /// <param name="loggerFactory">The logger factory.</param>
+    /// <param name="registeredDatasetOptions">Registered dataset options from DI.</param>
+    /// <param name="runtimeOptions">Runtime feature flags.</param>
+    /// <param name="peerOplogConfirmationStore">Optional peer confirmation store.</param>
+    /// <param name="handshakeService">Optional handshake service.</param>
+    /// <param name="telemetry">Optional telemetry service.</param>
+    /// <param name="oplogPruneCutoffCalculator">Optional prune cutoff calculator.</param>
+    /// <param name="orchestratorFactory">Optional factory override for dataset orchestrators (used by tests).</param>
+    public MultiDatasetSyncOrchestrator(
+        IDiscoveryService discovery,
+        IOplogStore oplogStore,
+        IDocumentStore documentStore,
+        ISnapshotMetadataStore snapshotMetadataStore,
+        ISnapshotService snapshotService,
+        IPeerNodeConfigurationProvider peerNodeConfigurationProvider,
+        ILoggerFactory loggerFactory,
+        IEnumerable<DatasetSyncOptions> registeredDatasetOptions,
+        MultiDatasetRuntimeOptions runtimeOptions,
+        IPeerOplogConfirmationStore? peerOplogConfirmationStore = null,
+        IPeerHandshakeService? handshakeService = null,
+        INetworkTelemetryService? telemetry = null,
+        IOplogPruneCutoffCalculator? oplogPruneCutoffCalculator = null,
+        Func<DatasetSyncOptions, ISyncOrchestrator>? orchestratorFactory = null)
+    {
+        _loggerFactory = loggerFactory;
+        _logger = loggerFactory.CreateLogger<MultiDatasetSyncOrchestrator>();
+
+        List<DatasetSyncOptions> datasets = BuildDatasetList(registeredDatasetOptions, runtimeOptions);
+        Contexts = datasets
+            .Select(options =>
+            {
+                var orchestrator = orchestratorFactory?.Invoke(options) ?? new SyncOrchestrator(
+                    discovery,
+                    oplogStore,
+                    documentStore,
+                    snapshotMetadataStore,
+                    snapshotService,
+                    peerNodeConfigurationProvider,
+                    loggerFactory,
+                    peerOplogConfirmationStore,
+                    handshakeService,
+                    telemetry,
+                    oplogPruneCutoffCalculator,
+                    options);
+
+                return (IDatasetSyncContext)new DatasetSyncContext(
+                    options.DatasetId,
+                    options,
+                    documentStore,
+                    oplogStore,
+                    snapshotMetadataStore,
+                    snapshotService,
+                    peerOplogConfirmationStore,
+                    orchestrator);
+            })
+            .ToList();
+    }
+
+    /// <inheritdoc />
+    public IReadOnlyCollection<IDatasetSyncContext> Contexts { get; }
+
+    /// <inheritdoc />
+    public async Task Start()
+    {
+        foreach (var context in Contexts)
+        {
+            if (!context.Options.Enabled) continue;
+
+            try
+            {
+                var runtimeContext = (DatasetSyncContext)context;
+                await runtimeContext.Orchestrator.Start();
+                _logger.LogInformation("Started dataset orchestrator: {DatasetId}", context.DatasetId);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Failed to start dataset orchestrator: {DatasetId}", context.DatasetId);
+            }
+        }
+    }
+
+    /// <inheritdoc />
+    public async Task Stop()
+    {
+        foreach (var context in Contexts)
+            try
+            {
+                var runtimeContext = (DatasetSyncContext)context;
+                await runtimeContext.Orchestrator.Stop();
+                _logger.LogInformation("Stopped dataset orchestrator: {DatasetId}", context.DatasetId);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Failed to stop dataset orchestrator: {DatasetId}", context.DatasetId);
+            }
+    }
+
+    private static List<DatasetSyncOptions> BuildDatasetList(
+        IEnumerable<DatasetSyncOptions> registeredDatasetOptions,
+        MultiDatasetRuntimeOptions runtimeOptions)
+    {
+        var optionMap = registeredDatasetOptions
+            .Select(Clone)
+            .GroupBy(o => DatasetId.Normalize(o.DatasetId))
+            .ToDictionary(g => g.Key, g => g.Last(), StringComparer.Ordinal);
+
+        foreach (var additional in runtimeOptions.AdditionalDatasets)
+            optionMap[DatasetId.Normalize(additional.DatasetId)] = Clone(additional);
+
+        if (!runtimeOptions.EnableMultiDatasetSync)
+            return
+            [
+                ResolveOrDefault(optionMap, DatasetId.Primary, enabled: true)
+            ];
+
+        var result = new List<DatasetSyncOptions>();
+        if (runtimeOptions.EnableDatasetPrimary)
+            result.Add(ResolveOrDefault(optionMap, DatasetId.Primary, enabled: true));
+
+        if (runtimeOptions.EnableDatasetLogs)
+            result.Add(ResolveOrDefault(optionMap, DatasetId.Logs, enabled: true));
+
+        if (runtimeOptions.EnableDatasetTimeseries)
+            result.Add(ResolveOrDefault(optionMap, DatasetId.Timeseries, enabled: true));
+
+        foreach (var kvp in optionMap)
+        {
+            if (string.Equals(kvp.Key, DatasetId.Primary, StringComparison.Ordinal)) continue;
+            if (string.Equals(kvp.Key, DatasetId.Logs, StringComparison.Ordinal)) continue;
+            if (string.Equals(kvp.Key, DatasetId.Timeseries, StringComparison.Ordinal)) continue;
+            result.Add(kvp.Value);
+        }
+
+        return result
+            .GroupBy(o => DatasetId.Normalize(o.DatasetId), StringComparer.Ordinal)
+            .Select(g => g.Last())
+            .ToList();
+    }
+
+    private static DatasetSyncOptions ResolveOrDefault(
+        IReadOnlyDictionary<string, DatasetSyncOptions> optionMap,
+        string datasetId,
+        bool enabled)
+    {
+        var normalized = DatasetId.Normalize(datasetId);
+        if (optionMap.TryGetValue(normalized, out var existing))
+        {
+            existing.DatasetId = normalized;
+            existing.Enabled = enabled && existing.Enabled;
+            return existing;
+        }
+
+        return new DatasetSyncOptions
+        {
+            DatasetId = normalized,
+            Enabled = enabled
+        };
+    }
+
+    private static DatasetSyncOptions Clone(DatasetSyncOptions options)
+    {
+        return new DatasetSyncOptions
+        {
+            DatasetId = DatasetId.Normalize(options.DatasetId),
+            Enabled = options.Enabled,
+            SyncLoopDelay = options.SyncLoopDelay,
+            MaxPeersPerCycle = options.MaxPeersPerCycle,
+            MaxEntriesPerCycle = options.MaxEntriesPerCycle,
+            MaintenanceIntervalOverride = options.MaintenanceIntervalOverride,
+            InterestingCollections = options.InterestingCollections.ToList()
+        };
+    }
+}

src/ZB.MOM.WW.CBDDC.Network/MultiDatasetSyncOrchestratorAdapter.cs

@@ -0,0 +1,32 @@
+using ZB.MOM.WW.CBDDC.Core.Storage;
+
+namespace ZB.MOM.WW.CBDDC.Network;
+
+/// <summary>
+///     Adapts <see cref="IMultiDatasetSyncOrchestrator" /> to <see cref="ISyncOrchestrator" />.
+/// </summary>
+internal sealed class MultiDatasetSyncOrchestratorAdapter : ISyncOrchestrator
+{
+    private readonly IMultiDatasetSyncOrchestrator _inner;
+
+    /// <summary>
+    ///     Initializes a new instance of the <see cref="MultiDatasetSyncOrchestratorAdapter" /> class.
+    /// </summary>
+    /// <param name="inner">The multi-dataset orchestrator.</param>
+    public MultiDatasetSyncOrchestratorAdapter(IMultiDatasetSyncOrchestrator inner)
+    {
+        _inner = inner;
+    }
+
+    /// <inheritdoc />
+    public Task Start()
+    {
+        return _inner.Start();
+    }
+
+    /// <inheritdoc />
+    public Task Stop()
+    {
+        return _inner.Stop();
+    }
+}

src/ZB.MOM.WW.CBDDC.Network/PeerDbNetworkExtensions.cs

@@ -1,6 +1,8 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Logging;
+using ZB.MOM.WW.CBDDC.Core;
+using ZB.MOM.WW.CBDDC.Core.Storage;
 using ZB.MOM.WW.CBDDC.Core.Network;
 using ZB.MOM.WW.CBDDC.Network.Security;
 using ZB.MOM.WW.CBDDC.Network.Telemetry;
@@ -52,4 +54,38 @@ public static class CBDDCNetworkExtensions
 
         return services;
     }
+
+    /// <summary>
+    ///     Enables multi-dataset orchestration and replaces the single orchestrator with a dataset coordinator.
+    /// </summary>
+    /// <param name="services">The service collection.</param>
+    /// <param name="configure">Optional configuration for runtime feature flags and dataset defaults.</param>
+    /// <returns>The service collection for chaining.</returns>
+    public static IServiceCollection AddCBDDCMultiDataset(
+        this IServiceCollection services,
+        Action<MultiDatasetRuntimeOptions>? configure = null)
+    {
+        var runtimeOptions = new MultiDatasetRuntimeOptions
+        {
+            EnableMultiDatasetSync = true,
+            EnableDatasetPrimary = true
+        };
+        configure?.Invoke(runtimeOptions);
+
+        services.AddSingleton(runtimeOptions);
+
+        // Ensure a primary dataset option exists for compatibility when callers did not register dataset options.
+        if (!services.Any(descriptor => descriptor.ServiceType == typeof(DatasetSyncOptions)))
+            services.AddSingleton(new DatasetSyncOptions
+            {
+                DatasetId = DatasetId.Primary,
+                Enabled = true
+            });
+
+        services.TryAddSingleton<IMultiDatasetSyncOrchestrator, MultiDatasetSyncOrchestrator>();
+        services.Replace(ServiceDescriptor.Singleton<ISyncOrchestrator>(sp =>
+            new MultiDatasetSyncOrchestratorAdapter(sp.GetRequiredService<IMultiDatasetSyncOrchestrator>())));
+
+        return services;
+    }
 }

src/ZB.MOM.WW.CBDDC.Network/SyncOrchestrator.cs

@@ -34,6 +34,8 @@ public class SyncOrchestrator : ISyncOrchestrator
     private readonly ISnapshotService _snapshotService;
     private readonly object _startStopLock = new();
     private readonly INetworkTelemetryService? _telemetry;
+    private readonly DatasetSyncOptions _datasetSyncOptions;
+    private readonly string _datasetId;
     private CancellationTokenSource? _cts;
 
     private DateTime _lastMaintenanceTime = DateTime.MinValue;
@@ -52,6 +54,7 @@ public class SyncOrchestrator : ISyncOrchestrator
     /// <param name="handshakeService">The optional peer handshake service.</param>
     /// <param name="telemetry">The optional network telemetry service.</param>
     /// <param name="oplogPruneCutoffCalculator">The optional cutoff calculator for safe maintenance pruning.</param>
+    /// <param name="datasetSyncOptions">The optional per-dataset synchronization options.</param>
     public SyncOrchestrator(
         IDiscoveryService discovery,
         IOplogStore oplogStore,
@@ -63,7 +66,8 @@ public class SyncOrchestrator : ISyncOrchestrator
         IPeerOplogConfirmationStore? peerOplogConfirmationStore = null,
         IPeerHandshakeService? handshakeService = null,
         INetworkTelemetryService? telemetry = null,
-        IOplogPruneCutoffCalculator? oplogPruneCutoffCalculator = null)
+        IOplogPruneCutoffCalculator? oplogPruneCutoffCalculator = null,
+        DatasetSyncOptions? datasetSyncOptions = null)
     {
         _discovery = discovery;
         _oplogStore = oplogStore;
@@ -77,6 +81,8 @@ public class SyncOrchestrator : ISyncOrchestrator
         _logger = loggerFactory.CreateLogger<SyncOrchestrator>();
         _handshakeService = handshakeService;
         _telemetry = telemetry;
+        _datasetSyncOptions = datasetSyncOptions ?? new DatasetSyncOptions();
+        _datasetId = DatasetId.Normalize(_datasetSyncOptions.DatasetId);
     }
 
     /// <summary>
@@ -166,7 +172,7 @@ public class SyncOrchestrator : ISyncOrchestrator
     /// </summary>
     private async Task SyncLoopAsync(CancellationToken token)
     {
-        _logger.LogInformation("Sync Orchestrator Started (Parallel P2P)");
+        _logger.LogInformation("Sync Orchestrator Started (Parallel P2P, Dataset: {DatasetId})", _datasetId);
         while (!token.IsCancellationRequested)
         {
             var config = await _peerNodeConfigurationProvider.GetConfiguration();
@@ -193,11 +199,11 @@ public class SyncOrchestrator : ISyncOrchestrator
                 }).ToList();
 
                 // Interest-Aware Gossip: Prioritize peers sharing interests with us
-                var localInterests = _documentStore.InterestedCollection.ToList();
+                var localInterests = GetDatasetInterests();
                 var targets = eligiblePeers
                     .OrderByDescending(p => p.InterestingCollections.Any(ci => localInterests.Contains(ci)))
                     .ThenBy(x => _random.Next())
-                    .Take(3)
+                    .Take(Math.Max(1, _datasetSyncOptions.MaxPeersPerCycle))
                     .ToList();
 
                 // NetStandard 2.0 fallback: Use Task.WhenAll
@@ -218,7 +224,7 @@ public class SyncOrchestrator : ISyncOrchestrator
 
             try
             {
-                await Task.Delay(2000, token);
+                await Task.Delay(_datasetSyncOptions.SyncLoopDelay, token);
             }
             catch (OperationCanceledException)
             {
@@ -236,7 +242,8 @@ public class SyncOrchestrator : ISyncOrchestrator
     /// <returns>A task that represents the asynchronous maintenance operation.</returns>
     internal async Task RunMaintenanceIfDueAsync(PeerNodeConfiguration config, DateTime now, CancellationToken token)
     {
-        var maintenanceInterval = TimeSpan.FromMinutes(config.MaintenanceIntervalMinutes);
+        var maintenanceInterval = _datasetSyncOptions.MaintenanceIntervalOverride ??
+                                  TimeSpan.FromMinutes(config.MaintenanceIntervalMinutes);
         if (now - _lastMaintenanceTime < maintenanceInterval) return;
 
         _logger.LogInformation("Running periodic maintenance (Oplog pruning)...");
@@ -253,7 +260,7 @@ public class SyncOrchestrator : ISyncOrchestrator
                 return;
             }
 
-            await _oplogStore.PruneOplogAsync(cutoffDecision.EffectiveCutoff.Value, token);
+            await _oplogStore.PruneOplogAsync(cutoffDecision.EffectiveCutoff.Value, _datasetId, token);
             _lastMaintenanceTime = now;
 
             if (cutoffDecision.ConfirmationCutoff.HasValue)
@@ -312,6 +319,7 @@ public class SyncOrchestrator : ISyncOrchestrator
         try
         {
             var config = await _peerNodeConfigurationProvider.GetConfiguration();
+            var localInterests = GetDatasetInterests();
 
             // Get or create persistent client
             client = _clients.GetOrAdd(peer.NodeId, id => new TcpPeerClient(
@@ -324,8 +332,8 @@ public class SyncOrchestrator : ISyncOrchestrator
             if (!client.IsConnected) await client.ConnectAsync(token);
 
             // Handshake (idempotent)
-            if (!await client.HandshakeAsync(config.NodeId, config.AuthToken, _documentStore.InterestedCollection,
+            if (!await client.HandshakeAsync(config.NodeId, config.AuthToken, localInterests,
-                    token))
+                    _datasetId, token))
             {
                 _logger.LogWarning("Handshake rejected by {NodeId}", peer.NodeId);
                 shouldRemoveClient = true;
@@ -334,7 +342,7 @@ public class SyncOrchestrator : ISyncOrchestrator
 
             // 1. Exchange Vector Clocks
             var remoteVectorClock = await client.GetVectorClockAsync(token);
-            var localVectorClock = await _oplogStore.GetVectorClockAsync(token);
+            var localVectorClock = await _oplogStore.GetVectorClockAsync(_datasetId, token);
 
             _logger.LogDebug("Vector Clock - Local: {Local}, Remote: {Remote}", localVectorClock, remoteVectorClock);
 
@@ -361,7 +369,7 @@ public class SyncOrchestrator : ISyncOrchestrator
 
                     // PASS LOCAL INTERESTS TO PULL
                     var changes = await client.PullChangesFromNodeAsync(nodeId, localTs,
-                        _documentStore.InterestedCollection, token);
+                        localInterests, _datasetId, token);
                     if (changes != null && changes.Count > 0)
                     {
                         var result = await ProcessInboundBatchAsync(client, peer.NodeId, changes, token);
@@ -390,13 +398,13 @@ public class SyncOrchestrator : ISyncOrchestrator
                     // PUSH FILTERING: Pass remote receiver's interests to oplogStore for efficient retrieval
                     var remoteInterests = client.RemoteInterests;
                     var changes =
-                        (await _oplogStore.GetOplogForNodeAfterAsync(nodeId, remoteTs, remoteInterests, token))
+                        (await _oplogStore.GetOplogForNodeAfterAsync(nodeId, remoteTs, _datasetId, remoteInterests, token))
                         .ToList();
 
                     if (changes.Any())
                     {
                         _logger.LogDebug("Pushing {Count} filtered changes for Node {NodeId}", changes.Count, nodeId);
-                        await client.PushChangesAsync(changes, token);
+                        await client.PushChangesAsync(changes, _datasetId, token);
                         await AdvanceConfirmationForPushedBatchAsync(peer.NodeId, nodeId, changes, token);
                     }
                 }
@@ -552,7 +560,7 @@ public class SyncOrchestrator : ISyncOrchestrator
             try
             {
                 await _peerOplogConfirmationStore.EnsurePeerRegisteredAsync(peer.NodeId, peer.Address, peer.Type,
-                    token);
+                    _datasetId, token);
             }
             catch (OperationCanceledException) when (token.IsCancellationRequested)
             {
@@ -623,6 +631,7 @@ public class SyncOrchestrator : ISyncOrchestrator
                 sourceNodeId,
                 maxPushed.Timestamp,
                 maxPushed.Hash ?? string.Empty,
+                _datasetId,
                 token);
         }
         catch (OperationCanceledException) when (token.IsCancellationRequested)
@@ -648,8 +657,14 @@ public class SyncOrchestrator : ISyncOrchestrator
         try
         {
             // Best-effort hash lookup: IOplogStore exposes latest hash per source node.
-            string hash = await _oplogStore.GetLastEntryHashAsync(sourceNodeId, token) ?? string.Empty;
+            string hash = await _oplogStore.GetLastEntryHashAsync(sourceNodeId, _datasetId, token) ?? string.Empty;
-            await _peerOplogConfirmationStore.UpdateConfirmationAsync(peerNodeId, sourceNodeId, timestamp, hash, token);
+            await _peerOplogConfirmationStore.UpdateConfirmationAsync(
+                peerNodeId,
+                sourceNodeId,
+                timestamp,
+                hash,
+                _datasetId,
+                token);
         }
         catch (OperationCanceledException) when (token.IsCancellationRequested)
         {
@@ -716,7 +731,7 @@ public class SyncOrchestrator : ISyncOrchestrator
 
             // Check linkage with Local State
             var firstEntry = authorChain[0];
-            string? localHeadHash = await _oplogStore.GetLastEntryHashAsync(authorNodeId, token);
+            string? localHeadHash = await _oplogStore.GetLastEntryHashAsync(authorNodeId, _datasetId, token);
 
             _logger.LogDebug(
                 "Processing chain for Node {AuthorId}: FirstEntry.PrevHash={PrevHash}, FirstEntry.Hash={Hash}, LocalHeadHash={LocalHead}",
@@ -725,7 +740,7 @@ public class SyncOrchestrator : ISyncOrchestrator
             if (localHeadHash != null && firstEntry.PreviousHash != localHeadHash)
             {
                 // Check if entry starts from snapshot boundary (valid case after pruning)
-                string? snapshotHash = await _snapshotMetadataStore.GetSnapshotHashAsync(authorNodeId, token);
+                string? snapshotHash = await _snapshotMetadataStore.GetSnapshotHashAsync(authorNodeId, _datasetId, token);
 
                 if (snapshotHash != null && firstEntry.PreviousHash == snapshotHash)
                 {
@@ -748,7 +763,7 @@ public class SyncOrchestrator : ISyncOrchestrator
                     List<OplogEntry>? missingChain = null;
                     try
                     {
-                        missingChain = await client.GetChainRangeAsync(localHeadHash, firstEntry.PreviousHash, token);
+                        missingChain = await client.GetChainRangeAsync(localHeadHash, firstEntry.PreviousHash, _datasetId, token);
                     }
                     catch (SnapshotRequiredException)
                     {
@@ -779,7 +794,7 @@ public class SyncOrchestrator : ISyncOrchestrator
                         }
 
                         // Apply Missing Chain First
-                        await _oplogStore.ApplyBatchAsync(missingChain, token);
+                        await _oplogStore.ApplyBatchAsync(missingChain, _datasetId, token);
                         _logger.LogInformation("Gap Recovery Applied Successfully.");
                     }
                     else
@@ -808,7 +823,7 @@ public class SyncOrchestrator : ISyncOrchestrator
             }
 
             // Apply original batch (grouped by node for clarity, but oplogStore usually handles bulk)
-            await _oplogStore.ApplyBatchAsync(authorChain, token);
+            await _oplogStore.ApplyBatchAsync(authorChain, _datasetId, token);
         }
 
         return SyncBatchResult.Success;
@@ -824,7 +839,7 @@ public class SyncOrchestrator : ISyncOrchestrator
             _logger.LogInformation("Downloading snapshot to {TempFile}...", tempFile);
             using (var fs = File.Create(tempFile))
             {
-                await client.GetSnapshotAsync(fs, token);
+                await client.GetSnapshotAsync(fs, _datasetId, token);
             }
 
             _logger.LogInformation("Snapshot Downloaded. applying to store...");
@@ -832,9 +847,9 @@ public class SyncOrchestrator : ISyncOrchestrator
             using (var fs = File.OpenRead(tempFile))
             {
                 if (mergeOnly)
-                    await _snapshotService.MergeSnapshotAsync(fs, token);
+                    await _snapshotService.MergeSnapshotAsync(fs, _datasetId, token);
                 else
-                    await _snapshotService.ReplaceDatabaseAsync(fs, token);
+                    await _snapshotService.ReplaceDatabaseAsync(fs, _datasetId, token);
             }
 
             _logger.LogInformation("Snapshot applied successfully.");
@@ -858,6 +873,17 @@ public class SyncOrchestrator : ISyncOrchestrator
         }
     }
 
+    private List<string> GetDatasetInterests()
+    {
+        if (_datasetSyncOptions.InterestingCollections.Count == 0)
+            return _documentStore.InterestedCollection.ToList();
+
+        return _datasetSyncOptions.InterestingCollections
+            .Where(value => !string.IsNullOrWhiteSpace(value))
+            .Distinct(StringComparer.Ordinal)
+            .ToList();
+    }
+
     private class PeerStatus
     {
         /// <summary>

src/ZB.MOM.WW.CBDDC.Network/TcpPeerClient.cs

@@ -170,7 +170,7 @@ public class TcpPeerClient : IDisposable
     /// <returns>True if handshake was accepted, false otherwise.</returns>
     public async Task<bool> HandshakeAsync(string myNodeId, string authToken, CancellationToken token)
     {
-        return await HandshakeAsync(myNodeId, authToken, null, token);
+        return await HandshakeAsync(myNodeId, authToken, null, DatasetId.Primary, token);
     }
 
     /// <summary>
@@ -183,15 +183,36 @@ public class TcpPeerClient : IDisposable
     /// <returns><see langword="true" /> if handshake was accepted; otherwise <see langword="false" />.</returns>
     public async Task<bool> HandshakeAsync(string myNodeId, string authToken,
         IEnumerable<string>? interestingCollections, CancellationToken token)
+    {
+        return await HandshakeAsync(myNodeId, authToken, interestingCollections, DatasetId.Primary, token);
+    }
+
+    /// <summary>
+    ///     Performs authentication handshake with the remote peer for a specific dataset.
+    /// </summary>
+    /// <param name="myNodeId">The local node identifier.</param>
+    /// <param name="authToken">The authentication token.</param>
+    /// <param name="interestingCollections">Optional collection names this node is interested in receiving.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="token">Cancellation token.</param>
+    /// <returns><see langword="true" /> if handshake was accepted; otherwise <see langword="false" />.</returns>
+    public async Task<bool> HandshakeAsync(string myNodeId, string authToken,
+        IEnumerable<string>? interestingCollections, string datasetId, CancellationToken token)
     {
         if (HasHandshaked) return true;
+        string normalizedDatasetId = DatasetId.Normalize(datasetId);
 
         if (_handshakeService != null)
             // Perform secure handshake if service is available
             // We assume we are initiator here
             _cipherState = await _handshakeService.HandshakeAsync(_stream!, true, myNodeId, token);
 
-        var req = new HandshakeRequest { NodeId = myNodeId, AuthToken = authToken ?? "" };
+        var req = new HandshakeRequest
+        {
+            NodeId = myNodeId,
+            AuthToken = authToken ?? "",
+            DatasetId = normalizedDatasetId
+        };
 
         if (interestingCollections != null)
             foreach (string coll in interestingCollections)
@@ -208,6 +229,13 @@ public class TcpPeerClient : IDisposable
         if (type != MessageType.HandshakeRes) return false;
 
         var res = HandshakeResponse.Parser.ParseFrom(payload);
+        string resolvedResponseDatasetId = DatasetId.Normalize(res.DatasetId);
+        if ((res.HasDatasetSupported && !res.DatasetSupported) ||
+            !string.Equals(resolvedResponseDatasetId, normalizedDatasetId, StringComparison.Ordinal))
+        {
+            HasHandshaked = false;
+            return false;
+        }
 
         // Store remote interests
         _remoteInterests = res.InterestingCollections.ToList();
@@ -276,7 +304,7 @@ public class TcpPeerClient : IDisposable
     /// <returns>The list of oplog entries returned by the remote peer.</returns>
     public async Task<List<OplogEntry>> PullChangesAsync(HlcTimestamp since, CancellationToken token)
     {
-        return await PullChangesAsync(since, null, token);
+        return await PullChangesAsync(since, null, DatasetId.Primary, token);
     }
 
     /// <summary>
@@ -289,12 +317,28 @@ public class TcpPeerClient : IDisposable
     public async Task<List<OplogEntry>> PullChangesAsync(HlcTimestamp since, IEnumerable<string>? collections,
         CancellationToken token)
     {
+        return await PullChangesAsync(since, collections, DatasetId.Primary, token);
+    }
+
+    /// <summary>
+    ///     Pulls oplog changes from the remote peer for a specific dataset.
+    /// </summary>
+    /// <param name="since">The starting timestamp for requested changes.</param>
+    /// <param name="collections">Optional collection names used to filter the returned entries.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="token">Cancellation token.</param>
+    /// <returns>The list of oplog entries returned by the remote peer.</returns>
+    public async Task<List<OplogEntry>> PullChangesAsync(HlcTimestamp since, IEnumerable<string>? collections,
+        string datasetId, CancellationToken token)
+    {
+        string normalizedDatasetId = DatasetId.Normalize(datasetId);
         var req = new PullChangesRequest
         {
             SinceWall = since.PhysicalTime,
             SinceLogic = since.LogicalCounter,
             // Empty SinceNode indicates a global pull (not source-node filtered).
-            SinceNode = string.Empty
+            SinceNode = string.Empty,
+            DatasetId = normalizedDatasetId
         };
         if (collections != null)
             foreach (string coll in collections)
@@ -315,7 +359,8 @@ public class TcpPeerClient : IDisposable
             string.IsNullOrEmpty(e.JsonData) ? default : JsonSerializer.Deserialize<JsonElement>(e.JsonData),
             new HlcTimestamp(e.HlcWall, e.HlcLogic, e.HlcNode),
             e.PreviousHash,
-            e.Hash // Pass the received hash to preserve integrity reference
+            e.Hash, // Pass the received hash to preserve integrity reference
+            string.IsNullOrWhiteSpace(e.DatasetId) ? normalizedDatasetId : e.DatasetId
         )).ToList();
     }
 
@@ -329,7 +374,7 @@ public class TcpPeerClient : IDisposable
     public async Task<List<OplogEntry>> PullChangesFromNodeAsync(string nodeId, HlcTimestamp since,
         CancellationToken token)
     {
-        return await PullChangesFromNodeAsync(nodeId, since, null, token);
+        return await PullChangesFromNodeAsync(nodeId, since, null, DatasetId.Primary, token);
     }
 
     /// <summary>
@@ -344,11 +389,28 @@ public class TcpPeerClient : IDisposable
     public async Task<List<OplogEntry>> PullChangesFromNodeAsync(string nodeId, HlcTimestamp since,
         IEnumerable<string>? collections, CancellationToken token)
     {
+        return await PullChangesFromNodeAsync(nodeId, since, collections, DatasetId.Primary, token);
+    }
+
+    /// <summary>
+    ///     Pulls oplog changes for a specific node and dataset from the remote peer.
+    /// </summary>
+    /// <param name="nodeId">The node identifier to filter changes by.</param>
+    /// <param name="since">The starting timestamp for requested changes.</param>
+    /// <param name="collections">Optional collection names used to filter the returned entries.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="token">Cancellation token.</param>
+    /// <returns>The list of oplog entries returned by the remote peer.</returns>
+    public async Task<List<OplogEntry>> PullChangesFromNodeAsync(string nodeId, HlcTimestamp since,
+        IEnumerable<string>? collections, string datasetId, CancellationToken token)
+    {
+        string normalizedDatasetId = DatasetId.Normalize(datasetId);
         var req = new PullChangesRequest
         {
             SinceNode = nodeId,
             SinceWall = since.PhysicalTime,
-            SinceLogic = since.LogicalCounter
+            SinceLogic = since.LogicalCounter,
+            DatasetId = normalizedDatasetId
         };
         if (collections != null)
             foreach (string coll in collections)
@@ -369,7 +431,8 @@ public class TcpPeerClient : IDisposable
             string.IsNullOrEmpty(e.JsonData) ? default : JsonSerializer.Deserialize<JsonElement>(e.JsonData),
             new HlcTimestamp(e.HlcWall, e.HlcLogic, e.HlcNode),
             e.PreviousHash,
-            e.Hash
+            e.Hash,
+            string.IsNullOrWhiteSpace(e.DatasetId) ? normalizedDatasetId : e.DatasetId
         )).ToList();
     }
 
@@ -383,7 +446,27 @@ public class TcpPeerClient : IDisposable
     public virtual async Task<List<OplogEntry>> GetChainRangeAsync(string startHash, string endHash,
         CancellationToken token)
     {
-        var req = new GetChainRangeRequest { StartHash = startHash, EndHash = endHash };
+        return await GetChainRangeAsync(startHash, endHash, DatasetId.Primary, token);
+    }
+
+    /// <summary>
+    ///     Retrieves a range of oplog entries connecting two hashes for a specific dataset.
+    /// </summary>
+    /// <param name="startHash">The starting hash in the chain.</param>
+    /// <param name="endHash">The ending hash in the chain.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="token">Cancellation token.</param>
+    /// <returns>The chain entries connecting the requested hash range.</returns>
+    public virtual async Task<List<OplogEntry>> GetChainRangeAsync(string startHash, string endHash,
+        string datasetId, CancellationToken token)
+    {
+        string normalizedDatasetId = DatasetId.Normalize(datasetId);
+        var req = new GetChainRangeRequest
+        {
+            StartHash = startHash,
+            EndHash = endHash,
+            DatasetId = normalizedDatasetId
+        };
         await _protocol.SendMessageAsync(_stream!, MessageType.GetChainRangeReq, req, _useCompression, _cipherState,
             token);
 
@@ -401,7 +484,8 @@ public class TcpPeerClient : IDisposable
             string.IsNullOrEmpty(e.JsonData) ? default : JsonSerializer.Deserialize<JsonElement>(e.JsonData),
             new HlcTimestamp(e.HlcWall, e.HlcLogic, e.HlcNode),
             e.PreviousHash,
-            e.Hash
+            e.Hash,
+            string.IsNullOrWhiteSpace(e.DatasetId) ? normalizedDatasetId : e.DatasetId
         )).ToList();
     }
 
@@ -413,7 +497,23 @@ public class TcpPeerClient : IDisposable
     /// <returns>A task that represents the asynchronous push operation.</returns>
     public async Task PushChangesAsync(IEnumerable<OplogEntry> entries, CancellationToken token)
     {
-        var req = new PushChangesRequest();
+        await PushChangesAsync(entries, DatasetId.Primary, token);
+    }
+
+    /// <summary>
+    ///     Pushes local oplog changes to the remote peer for a specific dataset.
+    /// </summary>
+    /// <param name="entries">The oplog entries to push.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="token">Cancellation token.</param>
+    /// <returns>A task that represents the asynchronous push operation.</returns>
+    public async Task PushChangesAsync(IEnumerable<OplogEntry> entries, string datasetId, CancellationToken token)
+    {
+        string normalizedDatasetId = DatasetId.Normalize(datasetId);
+        var req = new PushChangesRequest
+        {
+            DatasetId = normalizedDatasetId
+        };
         var entryList = entries.ToList();
         if (entryList.Count == 0) return;
 
@@ -428,7 +528,8 @@ public class TcpPeerClient : IDisposable
                 HlcLogic = e.Timestamp.LogicalCounter,
                 HlcNode = e.Timestamp.NodeId,
                 Hash = e.Hash,
-                PreviousHash = e.PreviousHash
+                PreviousHash = e.PreviousHash,
+                DatasetId = string.IsNullOrWhiteSpace(e.DatasetId) ? normalizedDatasetId : e.DatasetId
             });
 
         await _protocol.SendMessageAsync(_stream!, MessageType.PushChangesReq, req, _useCompression, _cipherState,
@@ -455,7 +556,22 @@ public class TcpPeerClient : IDisposable
     /// <returns>A task that represents the asynchronous snapshot transfer operation.</returns>
     public async Task GetSnapshotAsync(Stream destination, CancellationToken token)
     {
-        await _protocol.SendMessageAsync(_stream!, MessageType.GetSnapshotReq, new GetSnapshotRequest(),
+        await GetSnapshotAsync(destination, DatasetId.Primary, token);
+    }
+
+    /// <summary>
+    ///     Downloads a full snapshot for a specific dataset from the remote peer.
+    /// </summary>
+    /// <param name="destination">The stream that receives snapshot bytes.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="token">Cancellation token.</param>
+    /// <returns>A task that represents the asynchronous snapshot transfer operation.</returns>
+    public async Task GetSnapshotAsync(Stream destination, string datasetId, CancellationToken token)
+    {
+        await _protocol.SendMessageAsync(_stream!, MessageType.GetSnapshotReq, new GetSnapshotRequest
+            {
+                DatasetId = DatasetId.Normalize(datasetId)
+            },
             _useCompression, _cipherState, token);
 
         while (true)

src/ZB.MOM.WW.CBDDC.Network/TcpSyncServer.cs

@@ -248,6 +248,7 @@ internal class TcpSyncServer : ISyncServer
                 var useCompression = false;
                 CipherState? cipherState = null;
                 List<string> remoteInterests = new();
+                string currentDatasetId = DatasetId.Primary;
 
                 // Perform Secure Handshake (if service is available)
                 var config = await _configProvider.GetConfiguration();
@@ -278,6 +279,8 @@ internal class TcpSyncServer : ISyncServer
                     {
                         var hReq = HandshakeRequest.Parser.ParseFrom(payload);
                         _logger.LogDebug("Received HandshakeReq from Node {NodeId}", hReq.NodeId);
+                        string requestedDatasetId = DatasetId.Normalize(hReq.DatasetId);
+                        currentDatasetId = requestedDatasetId;
 
                         // Track remote peer interests
                         remoteInterests = hReq.InterestingCollections.ToList();
@@ -292,7 +295,13 @@ internal class TcpSyncServer : ISyncServer
                             return;
                         }
 
-                        var hRes = new HandshakeResponse { NodeId = config.NodeId, Accepted = true };
+                        var hRes = new HandshakeResponse
+                        {
+                            NodeId = config.NodeId,
+                            Accepted = true,
+                            DatasetId = requestedDatasetId,
+                            DatasetSupported = true
+                        };
 
                         // Include local interests from IDocumentStore in response for push filtering
                         foreach (string coll in _documentStore.InterestedCollection)
@@ -315,7 +324,7 @@ internal class TcpSyncServer : ISyncServer
                     switch (type)
                     {
                         case MessageType.GetClockReq:
-                            var clock = await _oplogStore.GetLatestTimestampAsync(token);
+                            var clock = await _oplogStore.GetLatestTimestampAsync(currentDatasetId, token);
                             response = new ClockResponse
                             {
                                 HlcWall = clock.PhysicalTime,
@@ -326,7 +335,7 @@ internal class TcpSyncServer : ISyncServer
                             break;
 
                         case MessageType.GetVectorClockReq:
-                            var vectorClock = await _oplogStore.GetVectorClockAsync(token);
+                            var vectorClock = await _oplogStore.GetVectorClockAsync(currentDatasetId, token);
                             var vcRes = new VectorClockResponse();
                             foreach (string nodeId in vectorClock.NodeIds)
                             {
@@ -345,13 +354,16 @@ internal class TcpSyncServer : ISyncServer
 
                         case MessageType.PullChangesReq:
                             var pReq = PullChangesRequest.Parser.ParseFrom(payload);
+                            string pullDatasetId = string.IsNullOrWhiteSpace(pReq.DatasetId)
+                                ? currentDatasetId
+                                : DatasetId.Normalize(pReq.DatasetId);
                             var since = new HlcTimestamp(pReq.SinceWall, pReq.SinceLogic, pReq.SinceNode);
 
                             // Use collection filter from request
                             var filter = pReq.Collections.Any() ? pReq.Collections : null;
                             var oplog = string.IsNullOrWhiteSpace(pReq.SinceNode)
-                                ? await _oplogStore.GetOplogAfterAsync(since, filter, token)
+                                ? await _oplogStore.GetOplogAfterAsync(since, pullDatasetId, filter, token)
-                                : await _oplogStore.GetOplogForNodeAfterAsync(pReq.SinceNode, since, filter, token);
+                                : await _oplogStore.GetOplogForNodeAfterAsync(pReq.SinceNode, since, pullDatasetId, filter, token);
 
                             var csRes = new ChangeSetResponse();
                             foreach (var e in oplog)
@@ -365,7 +377,8 @@ internal class TcpSyncServer : ISyncServer
                                     HlcLogic = e.Timestamp.LogicalCounter,
                                     HlcNode = e.Timestamp.NodeId,
                                     Hash = e.Hash,
-                                    PreviousHash = e.PreviousHash
+                                    PreviousHash = e.PreviousHash,
+                                    DatasetId = e.DatasetId
                                 });
                             response = csRes;
                             resType = MessageType.ChangeSetRes;
@@ -373,6 +386,9 @@ internal class TcpSyncServer : ISyncServer
 
                         case MessageType.PushChangesReq:
                             var pushReq = PushChangesRequest.Parser.ParseFrom(payload);
+                            string pushDatasetId = string.IsNullOrWhiteSpace(pushReq.DatasetId)
+                                ? currentDatasetId
+                                : DatasetId.Normalize(pushReq.DatasetId);
                             var entries = pushReq.Entries.Select(e => new OplogEntry(
                                 e.Collection,
                                 e.Key,
@@ -382,10 +398,11 @@ internal class TcpSyncServer : ISyncServer
                                     : JsonSerializer.Deserialize<JsonElement>(e.JsonData),
                                 new HlcTimestamp(e.HlcWall, e.HlcLogic, e.HlcNode),
                                 e.PreviousHash, // Restore PreviousHash
-                                e.Hash // Restore Hash
+                                e.Hash, // Restore Hash
+                                string.IsNullOrWhiteSpace(e.DatasetId) ? pushDatasetId : e.DatasetId
                             ));
 
-                            await _oplogStore.ApplyBatchAsync(entries, token);
+                            await _oplogStore.ApplyBatchAsync(entries, pushDatasetId, token);
 
                             response = new AckResponse { Success = true };
                             resType = MessageType.AckRes;
@@ -393,8 +410,15 @@ internal class TcpSyncServer : ISyncServer
 
                         case MessageType.GetChainRangeReq:
                             var rangeReq = GetChainRangeRequest.Parser.ParseFrom(payload);
+                            string chainDatasetId = string.IsNullOrWhiteSpace(rangeReq.DatasetId)
+                                ? currentDatasetId
+                                : DatasetId.Normalize(rangeReq.DatasetId);
                             var rangeEntries =
-                                await _oplogStore.GetChainRangeAsync(rangeReq.StartHash, rangeReq.EndHash, token);
+                                await _oplogStore.GetChainRangeAsync(
+                                    rangeReq.StartHash,
+                                    rangeReq.EndHash,
+                                    chainDatasetId,
+                                    token);
                             var rangeRes = new ChainRangeResponse();
 
                             if (!rangeEntries.Any() && rangeReq.StartHash != rangeReq.EndHash)
@@ -412,7 +436,8 @@ internal class TcpSyncServer : ISyncServer
                                         HlcLogic = e.Timestamp.LogicalCounter,
                                         HlcNode = e.Timestamp.NodeId,
                                         Hash = e.Hash,
-                                        PreviousHash = e.PreviousHash
+                                        PreviousHash = e.PreviousHash,
+                                        DatasetId = e.DatasetId
                                     });
 
                             response = rangeRes;
@@ -420,6 +445,10 @@ internal class TcpSyncServer : ISyncServer
                             break;
 
                         case MessageType.GetSnapshotReq:
+                            var snapshotRequest = GetSnapshotRequest.Parser.ParseFrom(payload);
+                            string snapshotDatasetId = string.IsNullOrWhiteSpace(snapshotRequest.DatasetId)
+                                ? currentDatasetId
+                                : DatasetId.Normalize(snapshotRequest.DatasetId);
                             _logger.LogInformation("Processing GetSnapshotReq from {Endpoint}", remoteEp);
                             string tempFile = Path.GetTempFileName();
                             try
@@ -427,7 +456,7 @@ internal class TcpSyncServer : ISyncServer
                                 // Create backup
                                 using (var fs = File.Create(tempFile))
                                 {
-                                    await _snapshotStore.CreateSnapshotAsync(fs, token);
+                                    await _snapshotStore.CreateSnapshotAsync(fs, snapshotDatasetId, token);
                                 }
 
                                 using (var fs = File.OpenRead(tempFile))

src/ZB.MOM.WW.CBDDC.Network/sync.proto

@@ -9,6 +9,7 @@ message HandshakeRequest {
   string auth_token = 2;
   repeated string supported_compression = 3; // v4
   repeated string interesting_collections = 4; // v5
+  string dataset_id = 5; // v6
 }
 
 message HandshakeResponse {
@@ -16,6 +17,8 @@ message HandshakeResponse {
   bool accepted = 2;
   string selected_compression = 3; // v4
   repeated string interesting_collections = 4; // v5
+  string dataset_id = 5; // v6
+  optional bool dataset_supported = 6; // v6
 }
 
 message GetClockRequest {
@@ -45,6 +48,7 @@ message PullChangesRequest {
   int32 since_logic = 2;
   string since_node = 3;
   repeated string collections = 4; // v5: Filter by collection
+  string dataset_id = 5; // v6
 }
 
 message ChangeSetResponse {
@@ -53,11 +57,13 @@ message ChangeSetResponse {
 
 message PushChangesRequest {
   repeated ProtoOplogEntry entries = 1;
+  string dataset_id = 2; // v6
 }
 
 message GetChainRangeRequest { 
   string start_hash = 1; 
   string end_hash = 2; 
+  string dataset_id = 3; // v6
 }
 
 message ChainRangeResponse { 
@@ -80,9 +86,11 @@ message ProtoOplogEntry {
   string hlc_node = 7;
   string hash = 8;
   string previous_hash = 9;
+  string dataset_id = 10; // v6
 }
 
 message GetSnapshotRequest {
+  string dataset_id = 1; // v6
 }
 
 message SnapshotChunk {

src/ZB.MOM.WW.CBDDC.Persistence/Snapshot/SnapshotDto.cs

@@ -20,6 +20,11 @@ public class SnapshotDto
     /// </summary>
     public string NodeId { get; set; } = "";
 
+    /// <summary>
+    ///     Gets or sets the dataset identifier represented by this snapshot payload.
+    /// </summary>
+    public string DatasetId { get; set; } = "primary";
+
     /// <summary>
     ///     Gets or sets the serialized document records.
     /// </summary>
@@ -48,6 +53,11 @@ public class SnapshotDto
 
 public class DocumentDto
 {
+    /// <summary>
+    ///     Gets or sets the dataset identifier.
+    /// </summary>
+    public string DatasetId { get; set; } = "primary";
+
     /// <summary>
     ///     Gets or sets the document collection name.
     /// </summary>
@@ -86,6 +96,11 @@ public class DocumentDto
 
 public class OplogDto
 {
+    /// <summary>
+    ///     Gets or sets the dataset identifier.
+    /// </summary>
+    public string DatasetId { get; set; } = "primary";
+
     /// <summary>
     ///     Gets or sets the collection associated with the operation.
     /// </summary>
@@ -134,6 +149,11 @@ public class OplogDto
 
 public class SnapshotMetadataDto
 {
+    /// <summary>
+    ///     Gets or sets the dataset identifier.
+    /// </summary>
+    public string DatasetId { get; set; } = "primary";
+
     /// <summary>
     ///     Gets or sets the node identifier.
     /// </summary>
@@ -180,6 +200,11 @@ public class RemotePeerDto
 
 public class PeerOplogConfirmationDto
 {
+    /// <summary>
+    ///     Gets or sets the dataset identifier.
+    /// </summary>
+    public string DatasetId { get; set; } = "primary";
+
     /// <summary>
     ///     Gets or sets the tracked peer node identifier.
     /// </summary>

src/ZB.MOM.WW.CBDDC.Persistence/SnapshotStore.cs

@@ -92,24 +92,43 @@ public class SnapshotStore : ISnapshotService
     /// <inheritdoc />
     public async Task CreateSnapshotAsync(Stream destination, CancellationToken cancellationToken = default)
     {
+        await CreateSnapshotAsync(destination, DatasetId.Primary, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task CreateSnapshotAsync(Stream destination, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = DatasetId.Normalize(datasetId);
         _logger.LogInformation("Creating snapshot...");
 
         var documents = await _documentStore.ExportAsync(cancellationToken);
         var remotePeers = await _peerConfigurationStore.ExportAsync(cancellationToken);
-        var oplogEntries = await _oplogStore.ExportAsync(cancellationToken);
+        var oplogEntries = (await _oplogStore.ExportAsync(normalizedDatasetId, cancellationToken)).ToList();
         var peerConfirmations = _peerOplogConfirmationStore == null
             ? []
-            : await _peerOplogConfirmationStore.ExportAsync(cancellationToken);
+            : await _peerOplogConfirmationStore.ExportAsync(normalizedDatasetId, cancellationToken);
+
+        if (!string.Equals(normalizedDatasetId, DatasetId.Primary, StringComparison.Ordinal))
+        {
+            var datasetDocumentKeys = oplogEntries
+                .Select(o => (o.Collection, o.Key))
+                .ToHashSet();
+            documents = documents.Where(document => datasetDocumentKeys.Contains((document.Collection, document.Key)));
+            remotePeers = [];
+        }
 
         var snapshot = new SnapshotDto
         {
             Version = "1.0",
             CreatedAt = DateTime.UtcNow.ToString("O"),
             NodeId = "", // Will be set by caller if needed
+            DatasetId = normalizedDatasetId,
             Documents =
             [
                 .. documents.Select(d => new DocumentDto
                 {
+                    DatasetId = normalizedDatasetId,
                     Collection = d.Collection,
                     Key = d.Key,
                     JsonData = d.Content.GetRawText(),
@@ -123,6 +142,7 @@ public class SnapshotStore : ISnapshotService
             [
                 .. oplogEntries.Select(o => new OplogDto
                 {
+                    DatasetId = o.DatasetId,
                     Collection = o.Collection,
                     Key = o.Key,
                     Operation = (int)o.Operation,
@@ -149,6 +169,7 @@ public class SnapshotStore : ISnapshotService
             [
                 .. peerConfirmations.Select(c => new PeerOplogConfirmationDto
                 {
+                    DatasetId = c.DatasetId,
                     PeerNodeId = c.PeerNodeId,
                     SourceNodeId = c.SourceNodeId,
                     ConfirmedWall = c.ConfirmedWall,
@@ -174,9 +195,17 @@ public class SnapshotStore : ISnapshotService
     /// <inheritdoc />
     public async Task ReplaceDatabaseAsync(Stream databaseStream, CancellationToken cancellationToken = default)
     {
+        await ReplaceDatabaseAsync(databaseStream, DatasetId.Primary, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task ReplaceDatabaseAsync(Stream databaseStream, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = DatasetId.Normalize(datasetId);
         _logger.LogWarning("Replacing data from snapshot stream...");
 
-        await ClearAllDataAsync(cancellationToken);
+        await ClearAllDataAsync(normalizedDatasetId, cancellationToken);
 
         var snapshot =
             await JsonSerializer.DeserializeAsync<SnapshotDto>(databaseStream, cancellationToken: cancellationToken);
@@ -198,7 +227,8 @@ public class SnapshotStore : ISnapshotService
                 : JsonSerializer.Deserialize<JsonElement>(o.JsonData),
             new HlcTimestamp(o.HlcWall, o.HlcLogic, o.HlcNode),
             o.PreviousHash ?? string.Empty,
-            string.IsNullOrWhiteSpace(o.Hash) ? null : o.Hash)).ToList();
+            string.IsNullOrWhiteSpace(o.Hash) ? null : o.Hash,
+            string.IsNullOrWhiteSpace(o.DatasetId) ? normalizedDatasetId : o.DatasetId)).ToList();
 
         var remotePeers = snapshot.RemotePeers.Select(p => new RemotePeerConfiguration
         {
@@ -210,6 +240,7 @@ public class SnapshotStore : ISnapshotService
         }).ToList();
         var peerConfirmations = (snapshot.PeerConfirmations ?? []).Select(c => new PeerOplogConfirmation
         {
+            DatasetId = string.IsNullOrWhiteSpace(c.DatasetId) ? normalizedDatasetId : c.DatasetId,
             PeerNodeId = c.PeerNodeId,
             SourceNodeId = c.SourceNodeId,
             ConfirmedWall = c.ConfirmedWall,
@@ -219,11 +250,15 @@ public class SnapshotStore : ISnapshotService
             IsActive = c.IsActive
         }).ToList();
 
+        if (string.Equals(normalizedDatasetId, DatasetId.Primary, StringComparison.Ordinal))
             await _documentStore.ImportAsync(documents, cancellationToken);
-        await _oplogStore.ImportAsync(oplogEntries, cancellationToken);
+        else
+            await _documentStore.MergeAsync(documents, cancellationToken);
+        await _oplogStore.ImportAsync(oplogEntries, normalizedDatasetId, cancellationToken);
+        if (string.Equals(normalizedDatasetId, DatasetId.Primary, StringComparison.Ordinal))
             await _peerConfigurationStore.ImportAsync(remotePeers, cancellationToken);
         if (_peerOplogConfirmationStore != null)
-            await _peerOplogConfirmationStore.ImportAsync(peerConfirmations, cancellationToken);
+            await _peerOplogConfirmationStore.ImportAsync(peerConfirmations, normalizedDatasetId, cancellationToken);
 
         _logger.LogInformation("Database replaced successfully.");
     }
@@ -231,6 +266,14 @@ public class SnapshotStore : ISnapshotService
     /// <inheritdoc />
     public async Task MergeSnapshotAsync(Stream snapshotStream, CancellationToken cancellationToken = default)
     {
+        await MergeSnapshotAsync(snapshotStream, DatasetId.Primary, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task MergeSnapshotAsync(Stream snapshotStream, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = DatasetId.Normalize(datasetId);
         _logger.LogInformation("Merging snapshot from stream...");
         var snapshot =
             await JsonSerializer.DeserializeAsync<SnapshotDto>(snapshotStream, cancellationToken: cancellationToken);
@@ -250,7 +293,8 @@ public class SnapshotStore : ISnapshotService
                 : JsonSerializer.Deserialize<JsonElement>(o.JsonData),
             new HlcTimestamp(o.HlcWall, o.HlcLogic, o.HlcNode),
             o.PreviousHash ?? string.Empty,
-            string.IsNullOrWhiteSpace(o.Hash) ? null : o.Hash)).ToList();
+            string.IsNullOrWhiteSpace(o.Hash) ? null : o.Hash,
+            string.IsNullOrWhiteSpace(o.DatasetId) ? normalizedDatasetId : o.DatasetId)).ToList();
         var remotePeers = snapshot.RemotePeers.Select(p => new RemotePeerConfiguration
         {
             NodeId = p.NodeId,
@@ -261,6 +305,7 @@ public class SnapshotStore : ISnapshotService
         }).ToList();
         var peerConfirmations = (snapshot.PeerConfirmations ?? []).Select(c => new PeerOplogConfirmation
         {
+            DatasetId = string.IsNullOrWhiteSpace(c.DatasetId) ? normalizedDatasetId : c.DatasetId,
             PeerNodeId = c.PeerNodeId,
             SourceNodeId = c.SourceNodeId,
             ConfirmedWall = c.ConfirmedWall,
@@ -271,19 +316,24 @@ public class SnapshotStore : ISnapshotService
         }).ToList();
 
         await _documentStore.MergeAsync(documents, cancellationToken);
-        await _oplogStore.MergeAsync(oplogEntries, cancellationToken);
+        await _oplogStore.MergeAsync(oplogEntries, normalizedDatasetId, cancellationToken);
+        if (string.Equals(normalizedDatasetId, DatasetId.Primary, StringComparison.Ordinal))
             await _peerConfigurationStore.MergeAsync(remotePeers, cancellationToken);
         if (_peerOplogConfirmationStore != null)
-            await _peerOplogConfirmationStore.MergeAsync(peerConfirmations, cancellationToken);
+            await _peerOplogConfirmationStore.MergeAsync(peerConfirmations, normalizedDatasetId, cancellationToken);
 
         _logger.LogInformation("Snapshot merged successfully.");
     }
 
-    private async Task ClearAllDataAsync(CancellationToken cancellationToken = default)
+    private async Task ClearAllDataAsync(string datasetId, CancellationToken cancellationToken = default)
+    {
+        await _oplogStore.DropAsync(datasetId, cancellationToken);
+        if (_peerOplogConfirmationStore != null) await _peerOplogConfirmationStore.DropAsync(datasetId, cancellationToken);
+
+        if (string.Equals(datasetId, DatasetId.Primary, StringComparison.Ordinal))
         {
             await _documentStore.DropAsync(cancellationToken);
             await _peerConfigurationStore.DropAsync(cancellationToken);
-        await _oplogStore.DropAsync(cancellationToken);
+        }
-        if (_peerOplogConfirmationStore != null) await _peerOplogConfirmationStore.DropAsync(cancellationToken);
     }
 }

src/ZB.MOM.WW.CBDDC.Persistence/Surreal/CBDDCSurrealEmbeddedExtensions.cs

@@ -1,5 +1,6 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
+using ZB.MOM.WW.CBDDC.Core;
 using ZB.MOM.WW.CBDDC.Core.Network;
 using SurrealDb.Net;
 using ZB.MOM.WW.CBDDC.Core.Storage;
@@ -46,6 +47,62 @@ public static class CBDDCSurrealEmbeddedExtensions
         return services;
     }
 
+    /// <summary>
+    ///     Registers dataset synchronization options for a Surreal-backed dataset pipeline.
+    /// </summary>
+    /// <param name="services">The service collection.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="configure">Optional per-dataset option overrides.</param>
+    /// <returns>The service collection for chaining.</returns>
+    public static IServiceCollection AddCBDDCSurrealEmbeddedDataset(
+        this IServiceCollection services,
+        string datasetId,
+        Action<DatasetSyncOptions>? configure = null)
+    {
+        if (services == null) throw new ArgumentNullException(nameof(services));
+
+        var options = new DatasetSyncOptions
+        {
+            DatasetId = DatasetId.Normalize(datasetId),
+            Enabled = true
+        };
+        configure?.Invoke(options);
+        options.DatasetId = DatasetId.Normalize(options.DatasetId);
+
+        services.AddSingleton(options);
+        return services;
+    }
+
+    /// <summary>
+    ///     Registers dataset synchronization options for a Surreal-backed dataset pipeline.
+    /// </summary>
+    /// <param name="services">The service collection.</param>
+    /// <param name="configure">Configuration delegate for dataset options.</param>
+    /// <returns>The service collection for chaining.</returns>
+    public static IServiceCollection AddCBDDCSurrealEmbeddedDataset(
+        this IServiceCollection services,
+        Action<DatasetSyncOptions> configure)
+    {
+        if (configure == null) throw new ArgumentNullException(nameof(configure));
+
+        var options = new DatasetSyncOptions
+        {
+            DatasetId = DatasetId.Primary,
+            Enabled = true
+        };
+        configure(options);
+
+        return services.AddCBDDCSurrealEmbeddedDataset(options.DatasetId, configured =>
+        {
+            configured.Enabled = options.Enabled;
+            configured.SyncLoopDelay = options.SyncLoopDelay;
+            configured.MaxPeersPerCycle = options.MaxPeersPerCycle;
+            configured.MaxEntriesPerCycle = options.MaxEntriesPerCycle;
+            configured.MaintenanceIntervalOverride = options.MaintenanceIntervalOverride;
+            configured.InterestingCollections = options.InterestingCollections.ToList();
+        });
+    }
+
     private static void RegisterCoreServices(
         IServiceCollection services,
         Func<IServiceProvider, CBDDCSurrealEmbeddedOptions> optionsFactory)

src/ZB.MOM.WW.CBDDC.Persistence/Surreal/CBDDCSurrealSchemaInitializer.cs

@@ -67,31 +67,31 @@ public sealed class CBDDCSurrealSchemaInitializer : ICBDDCSurrealSchemaInitializ
     {
         return $"""
                 DEFINE TABLE OVERWRITE {CBDDCSurrealSchemaNames.OplogEntriesTable} SCHEMAFULL CHANGEFEED {_changefeedRetentionLiteral};
-                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.OplogHashIndex} ON TABLE {CBDDCSurrealSchemaNames.OplogEntriesTable} COLUMNS hash UNIQUE;
+                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.OplogHashIndex} ON TABLE {CBDDCSurrealSchemaNames.OplogEntriesTable} COLUMNS datasetId, hash UNIQUE;
-                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.OplogHlcIndex} ON TABLE {CBDDCSurrealSchemaNames.OplogEntriesTable} COLUMNS timestampPhysicalTime, timestampLogicalCounter, timestampNodeId;
+                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.OplogHlcIndex} ON TABLE {CBDDCSurrealSchemaNames.OplogEntriesTable} COLUMNS datasetId, timestampPhysicalTime, timestampLogicalCounter, timestampNodeId;
-                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.OplogCollectionIndex} ON TABLE {CBDDCSurrealSchemaNames.OplogEntriesTable} COLUMNS collection;
+                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.OplogCollectionIndex} ON TABLE {CBDDCSurrealSchemaNames.OplogEntriesTable} COLUMNS datasetId, collection;
 
                 DEFINE TABLE OVERWRITE {CBDDCSurrealSchemaNames.SnapshotMetadataTable} SCHEMAFULL CHANGEFEED {_changefeedRetentionLiteral};
-                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.SnapshotNodeIdIndex} ON TABLE {CBDDCSurrealSchemaNames.SnapshotMetadataTable} COLUMNS nodeId UNIQUE;
+                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.SnapshotNodeIdIndex} ON TABLE {CBDDCSurrealSchemaNames.SnapshotMetadataTable} COLUMNS datasetId, nodeId UNIQUE;
-                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.SnapshotHlcIndex} ON TABLE {CBDDCSurrealSchemaNames.SnapshotMetadataTable} COLUMNS timestampPhysicalTime, timestampLogicalCounter;
+                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.SnapshotHlcIndex} ON TABLE {CBDDCSurrealSchemaNames.SnapshotMetadataTable} COLUMNS datasetId, timestampPhysicalTime, timestampLogicalCounter;
 
                 DEFINE TABLE OVERWRITE {CBDDCSurrealSchemaNames.RemotePeerConfigurationsTable} SCHEMAFULL CHANGEFEED {_changefeedRetentionLiteral};
                 DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.PeerNodeIdIndex} ON TABLE {CBDDCSurrealSchemaNames.RemotePeerConfigurationsTable} COLUMNS nodeId UNIQUE;
                 DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.PeerEnabledIndex} ON TABLE {CBDDCSurrealSchemaNames.RemotePeerConfigurationsTable} COLUMNS isEnabled;
 
                 DEFINE TABLE OVERWRITE {CBDDCSurrealSchemaNames.DocumentMetadataTable} SCHEMAFULL CHANGEFEED {_changefeedRetentionLiteral};
-                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.DocumentMetadataCollectionKeyIndex} ON TABLE {CBDDCSurrealSchemaNames.DocumentMetadataTable} COLUMNS collection, key UNIQUE;
+                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.DocumentMetadataCollectionKeyIndex} ON TABLE {CBDDCSurrealSchemaNames.DocumentMetadataTable} COLUMNS datasetId, collection, key UNIQUE;
-                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.DocumentMetadataHlcIndex} ON TABLE {CBDDCSurrealSchemaNames.DocumentMetadataTable} COLUMNS hlcPhysicalTime, hlcLogicalCounter, hlcNodeId;
+                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.DocumentMetadataHlcIndex} ON TABLE {CBDDCSurrealSchemaNames.DocumentMetadataTable} COLUMNS datasetId, hlcPhysicalTime, hlcLogicalCounter, hlcNodeId;
-                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.DocumentMetadataCollectionIndex} ON TABLE {CBDDCSurrealSchemaNames.DocumentMetadataTable} COLUMNS collection;
+                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.DocumentMetadataCollectionIndex} ON TABLE {CBDDCSurrealSchemaNames.DocumentMetadataTable} COLUMNS datasetId, collection;
 
                 DEFINE TABLE OVERWRITE {CBDDCSurrealSchemaNames.PeerOplogConfirmationsTable} SCHEMAFULL CHANGEFEED {_changefeedRetentionLiteral};
-                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.PeerConfirmationPairIndex} ON TABLE {CBDDCSurrealSchemaNames.PeerOplogConfirmationsTable} COLUMNS peerNodeId, sourceNodeId UNIQUE;
+                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.PeerConfirmationPairIndex} ON TABLE {CBDDCSurrealSchemaNames.PeerOplogConfirmationsTable} COLUMNS datasetId, peerNodeId, sourceNodeId UNIQUE;
-                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.PeerConfirmationActiveIndex} ON TABLE {CBDDCSurrealSchemaNames.PeerOplogConfirmationsTable} COLUMNS isActive;
+                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.PeerConfirmationActiveIndex} ON TABLE {CBDDCSurrealSchemaNames.PeerOplogConfirmationsTable} COLUMNS datasetId, isActive;
-                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.PeerConfirmationSourceHlcIndex} ON TABLE {CBDDCSurrealSchemaNames.PeerOplogConfirmationsTable} COLUMNS sourceNodeId, confirmedWall, confirmedLogic;
+                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.PeerConfirmationSourceHlcIndex} ON TABLE {CBDDCSurrealSchemaNames.PeerOplogConfirmationsTable} COLUMNS datasetId, sourceNodeId, confirmedWall, confirmedLogic;
 
                 DEFINE TABLE OVERWRITE {_checkpointTable} SCHEMAFULL;
-                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.CdcCheckpointConsumerIndex} ON TABLE {_checkpointTable} COLUMNS consumerId UNIQUE;
+                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.CdcCheckpointConsumerIndex} ON TABLE {_checkpointTable} COLUMNS datasetId, consumerId UNIQUE;
-                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.CdcCheckpointVersionstampIndex} ON TABLE {_checkpointTable} COLUMNS versionstampCursor;
+                DEFINE INDEX OVERWRITE {CBDDCSurrealSchemaNames.CdcCheckpointVersionstampIndex} ON TABLE {_checkpointTable} COLUMNS datasetId, versionstampCursor;
                 """;
     }
 

src/ZB.MOM.WW.CBDDC.Persistence/Surreal/ISurrealCdcCheckpointPersistence.cs

@@ -7,6 +7,11 @@ namespace ZB.MOM.WW.CBDDC.Persistence.Surreal;
 /// </summary>
 public sealed class SurrealCdcCheckpoint
 {
+    /// <summary>
+    ///     Gets or sets the dataset identifier.
+    /// </summary>
+    public string DatasetId { get; set; } = global::ZB.MOM.WW.CBDDC.Core.DatasetId.Primary;
+
     /// <summary>
     ///     Gets or sets the logical consumer identifier.
     /// </summary>
@@ -48,6 +53,21 @@ public interface ISurrealCdcCheckpointPersistence
         string? consumerId = null,
         CancellationToken cancellationToken = default);
 
+    /// <summary>
+    ///     Reads the checkpoint for a consumer within a specific dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="consumerId">Optional consumer id.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>The checkpoint if found; otherwise <see langword="null" />.</returns>
+    Task<SurrealCdcCheckpoint?> GetCheckpointAsync(
+        string datasetId,
+        string? consumerId,
+        CancellationToken cancellationToken = default)
+    {
+        return GetCheckpointAsync(consumerId, cancellationToken);
+    }
+
     /// <summary>
     ///     Upserts checkpoint progress for a consumer.
     /// </summary>
@@ -63,6 +83,26 @@ public interface ISurrealCdcCheckpointPersistence
         CancellationToken cancellationToken = default,
         long? versionstampCursor = null);
 
+    /// <summary>
+    ///     Upserts checkpoint progress for a consumer and dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="timestamp">The last processed timestamp.</param>
+    /// <param name="lastHash">The last processed hash.</param>
+    /// <param name="consumerId">Optional consumer id.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <param name="versionstampCursor">Optional changefeed versionstamp cursor.</param>
+    Task UpsertCheckpointAsync(
+        string datasetId,
+        HlcTimestamp timestamp,
+        string lastHash,
+        string? consumerId = null,
+        CancellationToken cancellationToken = default,
+        long? versionstampCursor = null)
+    {
+        return UpsertCheckpointAsync(timestamp, lastHash, consumerId, cancellationToken, versionstampCursor);
+    }
+
     /// <summary>
     ///     Advances checkpoint progress from an oplog entry.
     /// </summary>
@@ -73,4 +113,20 @@ public interface ISurrealCdcCheckpointPersistence
         OplogEntry entry,
         string? consumerId = null,
         CancellationToken cancellationToken = default);
+
+    /// <summary>
+    ///     Advances checkpoint progress for a specific dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="entry">The oplog entry that was processed.</param>
+    /// <param name="consumerId">Optional consumer id.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    Task AdvanceCheckpointAsync(
+        string datasetId,
+        OplogEntry entry,
+        string? consumerId = null,
+        CancellationToken cancellationToken = default)
+    {
+        return AdvanceCheckpointAsync(entry, consumerId, cancellationToken);
+    }
 }

src/ZB.MOM.WW.CBDDC.Persistence/Surreal/SurrealCdcCheckpointPersistence.cs

@@ -49,11 +49,21 @@ public sealed class SurrealCdcCheckpointPersistence : ISurrealCdcCheckpointPersi
     public async Task<SurrealCdcCheckpoint?> GetCheckpointAsync(
         string? consumerId = null,
         CancellationToken cancellationToken = default)
+    {
+        return await GetCheckpointAsync(DatasetId.Primary, consumerId, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task<SurrealCdcCheckpoint?> GetCheckpointAsync(
+        string datasetId,
+        string? consumerId,
+        CancellationToken cancellationToken = default)
     {
         if (!_enabled) return null;
 
         string resolvedConsumerId = ResolveConsumerId(consumerId);
-        var existing = await FindByConsumerIdAsync(resolvedConsumerId, cancellationToken);
+        string resolvedDatasetId = DatasetId.Normalize(datasetId);
+        var existing = await FindByConsumerIdAsync(resolvedDatasetId, resolvedConsumerId, cancellationToken);
         return existing?.ToDomain();
     }
 
@@ -64,26 +74,47 @@ public sealed class SurrealCdcCheckpointPersistence : ISurrealCdcCheckpointPersi
         string? consumerId = null,
         CancellationToken cancellationToken = default,
         long? versionstampCursor = null)
+    {
+        await UpsertCheckpointAsync(
+            DatasetId.Primary,
+            timestamp,
+            lastHash,
+            consumerId,
+            cancellationToken,
+            versionstampCursor);
+    }
+
+    /// <inheritdoc />
+    public async Task UpsertCheckpointAsync(
+        string datasetId,
+        HlcTimestamp timestamp,
+        string lastHash,
+        string? consumerId = null,
+        CancellationToken cancellationToken = default,
+        long? versionstampCursor = null)
     {
         if (!_enabled) return;
 
         string resolvedConsumerId = ResolveConsumerId(consumerId);
+        string resolvedDatasetId = DatasetId.Normalize(datasetId);
         await EnsureReadyAsync(cancellationToken);
 
         long? effectiveVersionstampCursor = versionstampCursor;
         if (!effectiveVersionstampCursor.HasValue)
         {
             var existing = await FindByConsumerIdAsync(
+                resolvedDatasetId,
                 resolvedConsumerId,
                 cancellationToken,
                 ensureInitialized: false);
             effectiveVersionstampCursor = existing?.VersionstampCursor;
         }
 
-        RecordId recordId = RecordId.From(_checkpointTable, ComputeConsumerKey(resolvedConsumerId));
+        RecordId recordId = RecordId.From(_checkpointTable, ComputeConsumerKey(resolvedDatasetId, resolvedConsumerId));
 
         var record = new SurrealCdcCheckpointRecord
         {
+            DatasetId = resolvedDatasetId,
             ConsumerId = resolvedConsumerId,
             TimestampPhysicalTime = timestamp.PhysicalTime,
             TimestampLogicalCounter = timestamp.LogicalCounter,
@@ -106,7 +137,18 @@ public sealed class SurrealCdcCheckpointPersistence : ISurrealCdcCheckpointPersi
         CancellationToken cancellationToken = default)
     {
         ArgumentNullException.ThrowIfNull(entry);
-        return UpsertCheckpointAsync(entry.Timestamp, entry.Hash, consumerId, cancellationToken);
+        return UpsertCheckpointAsync(entry.DatasetId, entry.Timestamp, entry.Hash, consumerId, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public Task AdvanceCheckpointAsync(
+        string datasetId,
+        OplogEntry entry,
+        string? consumerId = null,
+        CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(entry);
+        return UpsertCheckpointAsync(datasetId, entry.Timestamp, entry.Hash, consumerId, cancellationToken);
     }
 
     private string ResolveConsumerId(string? consumerId)
@@ -124,32 +166,44 @@ public sealed class SurrealCdcCheckpointPersistence : ISurrealCdcCheckpointPersi
     }
 
     private async Task<SurrealCdcCheckpointRecord?> FindByConsumerIdAsync(
+        string datasetId,
         string consumerId,
         CancellationToken cancellationToken,
         bool ensureInitialized = true)
     {
+        string normalizedDatasetId = DatasetId.Normalize(datasetId);
         if (ensureInitialized) await EnsureReadyAsync(cancellationToken);
 
-        RecordId deterministicId = RecordId.From(_checkpointTable, ComputeConsumerKey(consumerId));
+        RecordId deterministicId = RecordId.From(_checkpointTable, ComputeConsumerKey(normalizedDatasetId, consumerId));
         var deterministic = await _surrealClient.Select<SurrealCdcCheckpointRecord>(deterministicId, cancellationToken);
         if (deterministic != null &&
+            string.Equals(deterministic.DatasetId, normalizedDatasetId, StringComparison.Ordinal) &&
             string.Equals(deterministic.ConsumerId, consumerId, StringComparison.Ordinal))
             return deterministic;
 
         var all = await _surrealClient.Select<SurrealCdcCheckpointRecord>(_checkpointTable, cancellationToken);
         return all?.FirstOrDefault(c =>
+            (string.IsNullOrWhiteSpace(c.DatasetId)
+                ? string.Equals(normalizedDatasetId, DatasetId.Primary, StringComparison.Ordinal)
+                : string.Equals(c.DatasetId, normalizedDatasetId, StringComparison.Ordinal)) &&
             string.Equals(c.ConsumerId, consumerId, StringComparison.Ordinal));
     }
 
-    private static string ComputeConsumerKey(string consumerId)
+    private static string ComputeConsumerKey(string datasetId, string consumerId)
     {
-        byte[] input = Encoding.UTF8.GetBytes(consumerId);
+        byte[] input = Encoding.UTF8.GetBytes($"{datasetId}\n{consumerId}");
         return Convert.ToHexString(SHA256.HashData(input)).ToLowerInvariant();
     }
 }
 
 internal sealed class SurrealCdcCheckpointRecord : Record
 {
+    /// <summary>
+    ///     Gets or sets the dataset identifier.
+    /// </summary>
+    [JsonPropertyName("datasetId")]
+    public string DatasetId { get; set; } = global::ZB.MOM.WW.CBDDC.Core.DatasetId.Primary;
+
     /// <summary>
     ///     Gets or sets the CDC consumer identifier.
     /// </summary>
@@ -204,6 +258,7 @@ internal static class SurrealCdcCheckpointRecordMappers
     {
         return new SurrealCdcCheckpoint
         {
+            DatasetId = string.IsNullOrWhiteSpace(record.DatasetId) ? DatasetId.Primary : record.DatasetId,
             ConsumerId = record.ConsumerId,
             Timestamp = new HlcTimestamp(
                 record.TimestampPhysicalTime,

src/ZB.MOM.WW.CBDDC.Persistence/Surreal/SurrealDocumentMetadataStore.cs

@@ -9,6 +9,7 @@ namespace ZB.MOM.WW.CBDDC.Persistence.Surreal;
 
 public class SurrealDocumentMetadataStore : DocumentMetadataStore
 {
+    private const string PrimaryDatasetId = DatasetId.Primary;
     private readonly ILogger<SurrealDocumentMetadataStore> _logger;
     private readonly ICBDDCSurrealSchemaInitializer _schemaInitializer;
     private readonly ISurrealDbClient _surrealClient;
@@ -30,11 +31,35 @@ public class SurrealDocumentMetadataStore : DocumentMetadataStore
         _logger = logger ?? NullLogger<SurrealDocumentMetadataStore>.Instance;
     }
 
+    private static string NormalizeDatasetId(string? datasetId)
+    {
+        return DatasetId.Normalize(datasetId);
+    }
+
+    private static bool MatchesDataset(string? recordDatasetId, string datasetId)
+    {
+        if (string.IsNullOrWhiteSpace(recordDatasetId))
+            return string.Equals(datasetId, PrimaryDatasetId, StringComparison.Ordinal);
+
+        return string.Equals(NormalizeDatasetId(recordDatasetId), datasetId, StringComparison.Ordinal);
+    }
+
     /// <inheritdoc />
     public override async Task<DocumentMetadata?> GetMetadataAsync(string collection, string key,
         CancellationToken cancellationToken = default)
     {
-        var existing = await FindByCollectionKeyAsync(collection, key, cancellationToken);
+        var existing = await FindByCollectionKeyAsync(collection, key, PrimaryDatasetId, cancellationToken);
+        return existing?.ToDomain();
+    }
+
+    /// <inheritdoc />
+    public async Task<DocumentMetadata?> GetMetadataAsync(
+        string collection,
+        string key,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        var existing = await FindByCollectionKeyAsync(collection, key, NormalizeDatasetId(datasetId), cancellationToken);
         return existing?.ToDomain();
     }
 
@@ -42,7 +67,20 @@ public class SurrealDocumentMetadataStore : DocumentMetadataStore
     public override async Task<IEnumerable<DocumentMetadata>> GetMetadataByCollectionAsync(string collection,
         CancellationToken cancellationToken = default)
     {
-        var all = await SelectAllAsync(cancellationToken);
+        var all = await SelectAllAsync(PrimaryDatasetId, cancellationToken);
+        return all
+            .Where(m => string.Equals(m.Collection, collection, StringComparison.Ordinal))
+            .Select(m => m.ToDomain())
+            .ToList();
+    }
+
+    /// <inheritdoc />
+    public async Task<IEnumerable<DocumentMetadata>> GetMetadataByCollectionAsync(
+        string collection,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        var all = await SelectAllAsync(NormalizeDatasetId(datasetId), cancellationToken);
         return all
             .Where(m => string.Equals(m.Collection, collection, StringComparison.Ordinal))
             .Select(m => m.ToDomain())
@@ -53,10 +91,26 @@ public class SurrealDocumentMetadataStore : DocumentMetadataStore
     public override async Task UpsertMetadataAsync(DocumentMetadata metadata,
         CancellationToken cancellationToken = default)
     {
+        await UpsertMetadataAsync(metadata, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task UpsertMetadataAsync(
+        DocumentMetadata metadata,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        metadata.DatasetId = normalizedDatasetId;
         await EnsureReadyAsync(cancellationToken);
 
-        var existing = await FindByCollectionKeyAsync(metadata.Collection, metadata.Key, cancellationToken);
+        var existing =
-        RecordId recordId = existing?.Id ?? SurrealStoreRecordIds.DocumentMetadata(metadata.Collection, metadata.Key);
+            await FindByCollectionKeyAsync(metadata.Collection, metadata.Key, normalizedDatasetId, cancellationToken);
+        RecordId recordId = existing?.Id ??
+                            SurrealStoreRecordIds.DocumentMetadata(
+                                metadata.Collection,
+                                metadata.Key,
+                                normalizedDatasetId);
 
         await _surrealClient.Upsert<SurrealDocumentMetadataRecord, SurrealDocumentMetadataRecord>(
             recordId,
@@ -67,24 +121,46 @@ public class SurrealDocumentMetadataStore : DocumentMetadataStore
     /// <inheritdoc />
     public override async Task UpsertMetadataBatchAsync(IEnumerable<DocumentMetadata> metadatas,
         CancellationToken cancellationToken = default)
+    {
+        await UpsertMetadataBatchAsync(metadatas, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task UpsertMetadataBatchAsync(IEnumerable<DocumentMetadata> metadatas,
+        string datasetId,
+        CancellationToken cancellationToken = default)
     {
         foreach (var metadata in metadatas)
-            await UpsertMetadataAsync(metadata, cancellationToken);
+            await UpsertMetadataAsync(metadata, datasetId, cancellationToken);
     }
 
     /// <inheritdoc />
     public override async Task MarkDeletedAsync(string collection, string key, HlcTimestamp timestamp,
         CancellationToken cancellationToken = default)
     {
-        var metadata = new DocumentMetadata(collection, key, timestamp, true);
+        await MarkDeletedAsync(collection, key, timestamp, PrimaryDatasetId, cancellationToken);
-        await UpsertMetadataAsync(metadata, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task MarkDeletedAsync(string collection, string key, HlcTimestamp timestamp, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        var metadata = new DocumentMetadata(collection, key, timestamp, true, datasetId);
+        await UpsertMetadataAsync(metadata, datasetId, cancellationToken);
     }
 
     /// <inheritdoc />
     public override async Task<IEnumerable<DocumentMetadata>> GetMetadataAfterAsync(HlcTimestamp since,
         IEnumerable<string>? collections = null, CancellationToken cancellationToken = default)
     {
-        var all = await SelectAllAsync(cancellationToken);
+        return await GetMetadataAfterAsync(since, PrimaryDatasetId, collections, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task<IEnumerable<DocumentMetadata>> GetMetadataAfterAsync(HlcTimestamp since, string datasetId,
+        IEnumerable<string>? collections = null, CancellationToken cancellationToken = default)
+    {
+        var all = await SelectAllAsync(NormalizeDatasetId(datasetId), cancellationToken);
         HashSet<string>? collectionSet = collections != null ? new HashSet<string>(collections) : null;
 
         return all
@@ -101,14 +177,45 @@ public class SurrealDocumentMetadataStore : DocumentMetadataStore
     /// <inheritdoc />
     public override async Task DropAsync(CancellationToken cancellationToken = default)
     {
-        await EnsureReadyAsync(cancellationToken);
+        await DropAsync(PrimaryDatasetId, cancellationToken);
-        await _surrealClient.Delete(CBDDCSurrealSchemaNames.DocumentMetadataTable, cancellationToken);
+    }
+
+    /// <summary>
+    ///     Drops all metadata rows for a dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    public async Task DropAsync(string datasetId, CancellationToken cancellationToken = default)
+    {
+        var rows = await SelectAllAsync(NormalizeDatasetId(datasetId), cancellationToken);
+        foreach (var row in rows)
+        {
+            var recordId = row.Id ??
+                           SurrealStoreRecordIds.DocumentMetadata(
+                               row.Collection,
+                               row.Key,
+                               NormalizeDatasetId(datasetId));
+            await _surrealClient.Delete(recordId, cancellationToken);
+        }
     }
 
     /// <inheritdoc />
     public override async Task<IEnumerable<DocumentMetadata>> ExportAsync(CancellationToken cancellationToken = default)
     {
-        var all = await SelectAllAsync(cancellationToken);
+        var all = await SelectAllAsync(PrimaryDatasetId, cancellationToken);
+        return all.Select(m => m.ToDomain()).ToList();
+    }
+
+    /// <summary>
+    ///     Exports metadata rows for a dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>The exported metadata rows.</returns>
+    public async Task<IEnumerable<DocumentMetadata>> ExportAsync(string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        var all = await SelectAllAsync(NormalizeDatasetId(datasetId), cancellationToken);
         return all.Select(m => m.ToDomain()).ToList();
     }
 
@@ -116,16 +223,42 @@ public class SurrealDocumentMetadataStore : DocumentMetadataStore
     public override async Task ImportAsync(IEnumerable<DocumentMetadata> items,
         CancellationToken cancellationToken = default)
     {
-        foreach (var item in items) await UpsertMetadataAsync(item, cancellationToken);
+        await ImportAsync(items, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <summary>
+    ///     Imports metadata rows into a dataset.
+    /// </summary>
+    /// <param name="items">The metadata items.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    public async Task ImportAsync(IEnumerable<DocumentMetadata> items, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        foreach (var item in items) await UpsertMetadataAsync(item, datasetId, cancellationToken);
     }
 
     /// <inheritdoc />
     public override async Task MergeAsync(IEnumerable<DocumentMetadata> items,
         CancellationToken cancellationToken = default)
     {
+        await MergeAsync(items, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <summary>
+    ///     Merges metadata rows into a dataset.
+    /// </summary>
+    /// <param name="items">The metadata items.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    public async Task MergeAsync(IEnumerable<DocumentMetadata> items, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         foreach (var item in items)
         {
-            var existing = await FindByCollectionKeyAsync(item.Collection, item.Key, cancellationToken);
+            item.DatasetId = normalizedDatasetId;
+            var existing = await FindByCollectionKeyAsync(item.Collection, item.Key, normalizedDatasetId, cancellationToken);
 
             if (existing == null)
             {
@@ -138,7 +271,8 @@ public class SurrealDocumentMetadataStore : DocumentMetadataStore
 
             if (item.UpdatedAt.CompareTo(existingTimestamp) <= 0) continue;
 
-            RecordId recordId = existing.Id ?? SurrealStoreRecordIds.DocumentMetadata(item.Collection, item.Key);
+            RecordId recordId =
+                existing.Id ?? SurrealStoreRecordIds.DocumentMetadata(item.Collection, item.Key, normalizedDatasetId);
             await EnsureReadyAsync(cancellationToken);
             await _surrealClient.Upsert<SurrealDocumentMetadataRecord, SurrealDocumentMetadataRecord>(
                 recordId,
@@ -152,27 +286,37 @@ public class SurrealDocumentMetadataStore : DocumentMetadataStore
         await _schemaInitializer.EnsureInitializedAsync(cancellationToken);
     }
 
-    private async Task<List<SurrealDocumentMetadataRecord>> SelectAllAsync(CancellationToken cancellationToken)
+    private async Task<List<SurrealDocumentMetadataRecord>> SelectAllAsync(string datasetId,
+        CancellationToken cancellationToken)
     {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         await EnsureReadyAsync(cancellationToken);
         var rows = await _surrealClient.Select<SurrealDocumentMetadataRecord>(
             CBDDCSurrealSchemaNames.DocumentMetadataTable,
             cancellationToken);
-        return rows?.ToList() ?? [];
+        return rows?
+                   .Where(row => MatchesDataset(row.DatasetId, normalizedDatasetId))
+                   .ToList()
+               ?? [];
     }
 
-    private async Task<SurrealDocumentMetadataRecord?> FindByCollectionKeyAsync(string collection, string key,
+    private async Task<SurrealDocumentMetadataRecord?> FindByCollectionKeyAsync(
+        string collection,
+        string key,
+        string datasetId,
         CancellationToken cancellationToken)
     {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         await EnsureReadyAsync(cancellationToken);
-        RecordId deterministicId = SurrealStoreRecordIds.DocumentMetadata(collection, key);
+        RecordId deterministicId = SurrealStoreRecordIds.DocumentMetadata(collection, key, normalizedDatasetId);
         var deterministic = await _surrealClient.Select<SurrealDocumentMetadataRecord>(deterministicId, cancellationToken);
         if (deterministic != null &&
+            MatchesDataset(deterministic.DatasetId, normalizedDatasetId) &&
             string.Equals(deterministic.Collection, collection, StringComparison.Ordinal) &&
             string.Equals(deterministic.Key, key, StringComparison.Ordinal))
             return deterministic;
 
-        var all = await SelectAllAsync(cancellationToken);
+        var all = await SelectAllAsync(normalizedDatasetId, cancellationToken);
         return all.FirstOrDefault(m =>
             string.Equals(m.Collection, collection, StringComparison.Ordinal) &&
             string.Equals(m.Key, key, StringComparison.Ordinal));

src/ZB.MOM.WW.CBDDC.Persistence/Surreal/SurrealDocumentStore.cs

@@ -1205,7 +1205,10 @@ public abstract class SurrealDocumentStore<TContext> : IDocumentStore, ISurrealC
         {
             ["oplogRecordId"] = SurrealStoreRecordIds.Oplog(oplogEntry.Hash),
             ["oplogRecord"] = oplogEntry.ToSurrealRecord(),
-            ["metadataRecordId"] = SurrealStoreRecordIds.DocumentMetadata(metadata.Collection, metadata.Key),
+            ["metadataRecordId"] = SurrealStoreRecordIds.DocumentMetadata(
+                metadata.Collection,
+                metadata.Key,
+                metadata.DatasetId),
             ["metadataRecord"] = metadata.ToSurrealRecord()
         };
 
@@ -1261,10 +1264,12 @@ public abstract class SurrealDocumentStore<TContext> : IDocumentStore, ISurrealC
         checkpointRecord = new Dictionary<string, object?>();
         if (!TryGetCheckpointSettings(out string checkpointTable, out string consumerId)) return false;
 
-        string consumerKey = ComputeConsumerKey(consumerId);
+        const string datasetId = DatasetId.Primary;
+        string consumerKey = ComputeConsumerKey(datasetId, consumerId);
         checkpointRecordId = RecordId.From(checkpointTable, consumerKey);
         checkpointRecord = new Dictionary<string, object?>
         {
+            ["datasetId"] = datasetId,
             ["consumerId"] = consumerId,
             ["timestampPhysicalTime"] = oplogEntry.Timestamp.PhysicalTime,
             ["timestampLogicalCounter"] = oplogEntry.Timestamp.LogicalCounter,
@@ -1294,10 +1299,12 @@ public abstract class SurrealDocumentStore<TContext> : IDocumentStore, ISurrealC
             ? long.MaxValue
             : (long)pendingCursorCheckpoint.Value.Cursor;
 
-        string consumerKey = ComputeConsumerKey(cursorConsumerId);
+        const string datasetId = DatasetId.Primary;
+        string consumerKey = ComputeConsumerKey(datasetId, cursorConsumerId);
         checkpointRecordId = RecordId.From(checkpointTable, consumerKey);
         checkpointRecord = new Dictionary<string, object?>
         {
+            ["datasetId"] = datasetId,
             ["consumerId"] = cursorConsumerId,
             ["timestampPhysicalTime"] = encodedCursor,
             ["timestampLogicalCounter"] = 0,
@@ -1329,9 +1336,9 @@ public abstract class SurrealDocumentStore<TContext> : IDocumentStore, ISurrealC
         return true;
     }
 
-    private static string ComputeConsumerKey(string consumerId)
+    private static string ComputeConsumerKey(string datasetId, string consumerId)
     {
-        byte[] bytes = Encoding.UTF8.GetBytes(consumerId);
+        byte[] bytes = Encoding.UTF8.GetBytes($"{datasetId}\n{consumerId}");
         return Convert.ToHexString(SHA256.HashData(bytes)).ToLowerInvariant();
     }
 

src/ZB.MOM.WW.CBDDC.Persistence/Surreal/SurrealOplogStore.cs

@@ -10,6 +10,7 @@ namespace ZB.MOM.WW.CBDDC.Persistence.Surreal;
 
 public class SurrealOplogStore : OplogStore
 {
+    private const string PrimaryDatasetId = DatasetId.Primary;
     private readonly ILogger<SurrealOplogStore> _logger;
     private readonly ICBDDCSurrealSchemaInitializer? _schemaInitializer;
     private readonly ISurrealDbClient? _surrealClient;
@@ -46,17 +47,38 @@ public class SurrealOplogStore : OplogStore
         InitializeVectorClock();
     }
 
+    private static string NormalizeDatasetId(string? datasetId)
+    {
+        return DatasetId.Normalize(datasetId);
+    }
+
+    private static bool MatchesDataset(string? recordDatasetId, string datasetId)
+    {
+        if (string.IsNullOrWhiteSpace(recordDatasetId))
+            return string.Equals(datasetId, PrimaryDatasetId, StringComparison.Ordinal);
+
+        return string.Equals(NormalizeDatasetId(recordDatasetId), datasetId, StringComparison.Ordinal);
+    }
+
     /// <inheritdoc />
     public override async Task<IEnumerable<OplogEntry>> GetChainRangeAsync(string startHash, string endHash,
         CancellationToken cancellationToken = default)
     {
-        var startRow = await FindByHashAsync(startHash, cancellationToken);
+        return await GetChainRangeAsync(startHash, endHash, PrimaryDatasetId, cancellationToken);
-        var endRow = await FindByHashAsync(endHash, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task<IEnumerable<OplogEntry>> GetChainRangeAsync(string startHash, string endHash, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        var startRow = await FindByHashAsync(startHash, normalizedDatasetId, cancellationToken);
+        var endRow = await FindByHashAsync(endHash, normalizedDatasetId, cancellationToken);
 
         if (startRow == null || endRow == null) return [];
 
         string nodeId = startRow.TimestampNodeId;
-        var all = await SelectAllAsync(cancellationToken);
+        var all = await SelectAllAsync(normalizedDatasetId, cancellationToken);
 
         return all
             .Where(o => string.Equals(o.TimestampNodeId, nodeId, StringComparison.Ordinal) &&
@@ -75,7 +97,16 @@ public class SurrealOplogStore : OplogStore
     /// <inheritdoc />
     public override async Task<OplogEntry?> GetEntryByHashAsync(string hash, CancellationToken cancellationToken = default)
     {
-        var existing = await FindByHashAsync(hash, cancellationToken);
+        var existing = await FindByHashAsync(hash, PrimaryDatasetId, cancellationToken);
+        return existing?.ToDomain();
+    }
+
+    /// <inheritdoc />
+    public async Task<OplogEntry?> GetEntryByHashAsync(string hash, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        var existing = await FindByHashAsync(hash, normalizedDatasetId, cancellationToken);
         return existing?.ToDomain();
     }
 
@@ -83,7 +114,15 @@ public class SurrealOplogStore : OplogStore
     public override async Task<IEnumerable<OplogEntry>> GetOplogAfterAsync(HlcTimestamp timestamp,
         IEnumerable<string>? collections = null, CancellationToken cancellationToken = default)
     {
-        var all = await SelectAllAsync(cancellationToken);
+        return await GetOplogAfterAsync(timestamp, PrimaryDatasetId, collections, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task<IEnumerable<OplogEntry>> GetOplogAfterAsync(HlcTimestamp timestamp, string datasetId,
+        IEnumerable<string>? collections = null, CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        var all = await SelectAllAsync(normalizedDatasetId, cancellationToken);
         HashSet<string>? collectionSet = collections != null ? new HashSet<string>(collections) : null;
 
         return all
@@ -102,7 +141,15 @@ public class SurrealOplogStore : OplogStore
     public override async Task<IEnumerable<OplogEntry>> GetOplogForNodeAfterAsync(string nodeId, HlcTimestamp since,
         IEnumerable<string>? collections = null, CancellationToken cancellationToken = default)
     {
-        var all = await SelectAllAsync(cancellationToken);
+        return await GetOplogForNodeAfterAsync(nodeId, since, PrimaryDatasetId, collections, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task<IEnumerable<OplogEntry>> GetOplogForNodeAfterAsync(string nodeId, HlcTimestamp since,
+        string datasetId, IEnumerable<string>? collections = null, CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        var all = await SelectAllAsync(normalizedDatasetId, cancellationToken);
         HashSet<string>? collectionSet = collections != null ? new HashSet<string>(collections) : null;
 
         return all
@@ -121,7 +168,15 @@ public class SurrealOplogStore : OplogStore
     /// <inheritdoc />
     public override async Task PruneOplogAsync(HlcTimestamp cutoff, CancellationToken cancellationToken = default)
     {
-        var all = await SelectAllAsync(cancellationToken);
+        await PruneOplogAsync(cutoff, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task PruneOplogAsync(HlcTimestamp cutoff, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        var all = await SelectAllAsync(normalizedDatasetId, cancellationToken);
         var toDelete = all
             .Where(o => o.TimestampPhysicalTime < cutoff.PhysicalTime ||
                         (o.TimestampPhysicalTime == cutoff.PhysicalTime &&
@@ -139,38 +194,114 @@ public class SurrealOplogStore : OplogStore
     /// <inheritdoc />
     public override async Task DropAsync(CancellationToken cancellationToken = default)
     {
-        await EnsureReadyAsync(cancellationToken);
+        await DropAsync(PrimaryDatasetId, cancellationToken);
-        await _surrealClient!.Delete(CBDDCSurrealSchemaNames.OplogEntriesTable, cancellationToken);
         _vectorClock.Invalidate();
     }
 
+    /// <summary>
+    ///     Drops all oplog rows for the specified dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    public async Task DropAsync(string datasetId, CancellationToken cancellationToken = default)
+    {
+        var rows = await SelectAllAsync(NormalizeDatasetId(datasetId), cancellationToken);
+        foreach (var row in rows)
+        {
+            RecordId recordId = row.Id ?? SurrealStoreRecordIds.Oplog(row.Hash);
+            await EnsureReadyAsync(cancellationToken);
+            await _surrealClient!.Delete(recordId, cancellationToken);
+        }
+    }
+
     /// <inheritdoc />
     public override async Task<IEnumerable<OplogEntry>> ExportAsync(CancellationToken cancellationToken = default)
     {
-        var all = await SelectAllAsync(cancellationToken);
+        var all = await SelectAllAsync(PrimaryDatasetId, cancellationToken);
+        return all.Select(o => o.ToDomain()).ToList();
+    }
+
+    /// <summary>
+    ///     Exports all oplog entries for a dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>All dataset-scoped oplog entries.</returns>
+    public async Task<IEnumerable<OplogEntry>> ExportAsync(string datasetId, CancellationToken cancellationToken = default)
+    {
+        var all = await SelectAllAsync(NormalizeDatasetId(datasetId), cancellationToken);
         return all.Select(o => o.ToDomain()).ToList();
     }
 
     /// <inheritdoc />
     public override async Task ImportAsync(IEnumerable<OplogEntry> items, CancellationToken cancellationToken = default)
     {
+        await ImportAsync(items, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <summary>
+    ///     Imports oplog entries for the specified dataset.
+    /// </summary>
+    /// <param name="items">The entries to import.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    public async Task ImportAsync(IEnumerable<OplogEntry> items, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        Dictionary<string, RecordId> existingByHash =
+            await LoadOplogRecordIdsByHashAsync(normalizedDatasetId, cancellationToken);
         foreach (var item in items)
         {
-            var existing = await FindByHashAsync(item.Hash, cancellationToken);
+            var normalizedItem = new OplogEntry(
-            RecordId recordId = existing?.Id ?? SurrealStoreRecordIds.Oplog(item.Hash);
+                item.Collection,
-            await UpsertAsync(item, recordId, cancellationToken);
+                item.Key,
+                item.Operation,
+                item.Payload,
+                item.Timestamp,
+                item.PreviousHash,
+                item.Hash,
+                normalizedDatasetId);
+            RecordId recordId = existingByHash.TryGetValue(item.Hash, out RecordId? existingRecordId)
+                ? existingRecordId
+                : SurrealStoreRecordIds.Oplog(item.Hash);
+            await UpsertAsync(normalizedItem, recordId, cancellationToken);
+            existingByHash[item.Hash] = recordId;
         }
     }
 
     /// <inheritdoc />
     public override async Task MergeAsync(IEnumerable<OplogEntry> items, CancellationToken cancellationToken = default)
     {
+        await MergeAsync(items, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <summary>
+    ///     Merges oplog entries into the specified dataset.
+    /// </summary>
+    /// <param name="items">The entries to merge.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    public async Task MergeAsync(IEnumerable<OplogEntry> items, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        HashSet<string> existingHashes = await LoadOplogHashesAsync(normalizedDatasetId, cancellationToken);
         foreach (var item in items)
         {
-            var existing = await FindByHashAsync(item.Hash, cancellationToken);
+            if (!existingHashes.Add(item.Hash))
-            if (existing != null) continue;
+                continue;
 
-            await UpsertAsync(item, SurrealStoreRecordIds.Oplog(item.Hash), cancellationToken);
+            var normalizedItem = new OplogEntry(
+                item.Collection,
+                item.Key,
+                item.Operation,
+                item.Payload,
+                item.Timestamp,
+                item.PreviousHash,
+                item.Hash,
+                normalizedDatasetId);
+            await UpsertAsync(normalizedItem, SurrealStoreRecordIds.Oplog(normalizedItem.Hash), cancellationToken);
         }
     }
 
@@ -190,6 +321,8 @@ public class SurrealOplogStore : OplogStore
             {
                 var snapshots = _snapshotMetadataStore.GetAllSnapshotMetadataAsync().GetAwaiter().GetResult();
                 foreach (var snapshot in snapshots)
+                {
+                    if (!MatchesDataset(snapshot.DatasetId, PrimaryDatasetId)) continue;
                     _vectorClock.UpdateNode(
                         snapshot.NodeId,
                         new HlcTimestamp(
@@ -198,6 +331,7 @@ public class SurrealOplogStore : OplogStore
                             snapshot.NodeId),
                         snapshot.Hash ?? "");
                 }
+            }
             catch
             {
                 // Ignore snapshot bootstrap failures to keep oplog fallback behavior aligned.
@@ -209,6 +343,7 @@ public class SurrealOplogStore : OplogStore
                   ?? [];
 
         var latestPerNode = all
+            .Where(x => MatchesDataset(x.DatasetId, PrimaryDatasetId))
             .Where(x => !string.IsNullOrWhiteSpace(x.TimestampNodeId))
             .GroupBy(x => x.TimestampNodeId)
             .Select(g => g
@@ -229,17 +364,27 @@ public class SurrealOplogStore : OplogStore
     /// <inheritdoc />
     protected override async Task InsertOplogEntryAsync(OplogEntry entry, CancellationToken cancellationToken = default)
     {
-        var existing = await FindByHashAsync(entry.Hash, cancellationToken);
+        string datasetId = NormalizeDatasetId(entry.DatasetId);
+        var normalizedEntry = new OplogEntry(
+            entry.Collection,
+            entry.Key,
+            entry.Operation,
+            entry.Payload,
+            entry.Timestamp,
+            entry.PreviousHash,
+            entry.Hash,
+            datasetId);
+        var existing = await FindByHashAsync(normalizedEntry.Hash, datasetId, cancellationToken);
         if (existing != null) return;
 
-        await UpsertAsync(entry, SurrealStoreRecordIds.Oplog(entry.Hash), cancellationToken);
+        await UpsertAsync(normalizedEntry, SurrealStoreRecordIds.Oplog(normalizedEntry.Hash), cancellationToken);
     }
 
     /// <inheritdoc />
     protected override async Task<string?> QueryLastHashForNodeAsync(string nodeId,
         CancellationToken cancellationToken = default)
     {
-        var all = await SelectAllAsync(cancellationToken);
+        var all = await SelectAllAsync(PrimaryDatasetId, cancellationToken);
         var lastEntry = all
             .Where(o => string.Equals(o.TimestampNodeId, nodeId, StringComparison.Ordinal))
             .OrderByDescending(o => o.TimestampPhysicalTime)
@@ -252,11 +397,106 @@ public class SurrealOplogStore : OplogStore
     protected override async Task<(long Wall, int Logic)?> QueryLastHashTimestampFromOplogAsync(string hash,
         CancellationToken cancellationToken = default)
     {
-        var existing = await FindByHashAsync(hash, cancellationToken);
+        var existing = await FindByHashAsync(hash, PrimaryDatasetId, cancellationToken);
         if (existing == null) return null;
         return (existing.TimestampPhysicalTime, existing.TimestampLogicalCounter);
     }
 
+    /// <inheritdoc />
+    public async Task AppendOplogEntryAsync(
+        OplogEntry entry,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        var normalizedEntry = new OplogEntry(
+            entry.Collection,
+            entry.Key,
+            entry.Operation,
+            entry.Payload,
+            entry.Timestamp,
+            entry.PreviousHash,
+            entry.Hash,
+            normalizedDatasetId);
+        await AppendOplogEntryAsync(normalizedEntry, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task<HlcTimestamp> GetLatestTimestampAsync(string datasetId, CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        var all = await SelectAllAsync(normalizedDatasetId, cancellationToken);
+        var latest = all
+            .OrderByDescending(o => o.TimestampPhysicalTime)
+            .ThenByDescending(o => o.TimestampLogicalCounter)
+            .FirstOrDefault();
+
+        return latest == null
+            ? new HlcTimestamp(0, 0, "")
+            : new HlcTimestamp(latest.TimestampPhysicalTime, latest.TimestampLogicalCounter, latest.TimestampNodeId);
+    }
+
+    /// <inheritdoc />
+    public async Task<VectorClock> GetVectorClockAsync(string datasetId, CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        var all = await SelectAllAsync(normalizedDatasetId, cancellationToken);
+        var vectorClock = new VectorClock();
+        foreach (var latest in all
+                     .Where(o => !string.IsNullOrWhiteSpace(o.TimestampNodeId))
+                     .GroupBy(o => o.TimestampNodeId)
+                     .Select(g => g.OrderByDescending(o => o.TimestampPhysicalTime)
+                         .ThenByDescending(o => o.TimestampLogicalCounter)
+                         .First()))
+            vectorClock.SetTimestamp(
+                latest.TimestampNodeId,
+                new HlcTimestamp(latest.TimestampPhysicalTime, latest.TimestampLogicalCounter, latest.TimestampNodeId));
+
+        return vectorClock;
+    }
+
+    /// <inheritdoc />
+    public async Task<string?> GetLastEntryHashAsync(string nodeId, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        var all = await SelectAllAsync(normalizedDatasetId, cancellationToken);
+        var latest = all
+            .Where(o => string.Equals(o.TimestampNodeId, nodeId, StringComparison.Ordinal))
+            .OrderByDescending(o => o.TimestampPhysicalTime)
+            .ThenByDescending(o => o.TimestampLogicalCounter)
+            .FirstOrDefault();
+
+        if (latest != null) return latest.Hash;
+
+        if (_snapshotMetadataStore == null) return null;
+        var snapshotHash =
+            await _snapshotMetadataStore.GetSnapshotHashAsync(nodeId, normalizedDatasetId, cancellationToken);
+        return snapshotHash;
+    }
+
+    /// <inheritdoc />
+    public async Task ApplyBatchAsync(
+        IEnumerable<OplogEntry> oplogEntries,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        var normalizedEntries = oplogEntries
+            .Select(entry => new OplogEntry(
+                entry.Collection,
+                entry.Key,
+                entry.Operation,
+                entry.Payload,
+                entry.Timestamp,
+                entry.PreviousHash,
+                entry.Hash,
+                normalizedDatasetId))
+            .ToList();
+
+        await ApplyBatchAsync(normalizedEntries, cancellationToken);
+    }
+
     private async Task UpsertAsync(OplogEntry entry, RecordId recordId, CancellationToken cancellationToken)
     {
         await EnsureReadyAsync(cancellationToken);
@@ -271,25 +511,56 @@ public class SurrealOplogStore : OplogStore
         await _schemaInitializer!.EnsureInitializedAsync(cancellationToken);
     }
 
-    private async Task<List<SurrealOplogRecord>> SelectAllAsync(CancellationToken cancellationToken)
+    private async Task<List<SurrealOplogRecord>> SelectAllAsync(string datasetId, CancellationToken cancellationToken)
     {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         await EnsureReadyAsync(cancellationToken);
         var rows = await _surrealClient!.Select<SurrealOplogRecord>(
             CBDDCSurrealSchemaNames.OplogEntriesTable,
             cancellationToken);
-        return rows?.ToList() ?? [];
+        return rows?
+                   .Where(row => MatchesDataset(row.DatasetId, normalizedDatasetId))
+                   .ToList()
+               ?? [];
     }
 
-    private async Task<SurrealOplogRecord?> FindByHashAsync(string hash, CancellationToken cancellationToken)
+    private async Task<SurrealOplogRecord?> FindByHashAsync(string hash, string datasetId, CancellationToken cancellationToken)
     {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         await EnsureReadyAsync(cancellationToken);
 
         RecordId deterministicId = SurrealStoreRecordIds.Oplog(hash);
         var deterministic = await _surrealClient!.Select<SurrealOplogRecord>(deterministicId, cancellationToken);
-        if (deterministic != null && string.Equals(deterministic.Hash, hash, StringComparison.Ordinal))
+        if (deterministic != null &&
+            string.Equals(deterministic.Hash, hash, StringComparison.Ordinal) &&
+            MatchesDataset(deterministic.DatasetId, normalizedDatasetId))
             return deterministic;
 
-        var all = await SelectAllAsync(cancellationToken);
+        var all = await SelectAllAsync(normalizedDatasetId, cancellationToken);
         return all.FirstOrDefault(o => string.Equals(o.Hash, hash, StringComparison.Ordinal));
     }
+
+    private async Task<HashSet<string>> LoadOplogHashesAsync(string datasetId, CancellationToken cancellationToken)
+    {
+        var rows = await SelectAllAsync(datasetId, cancellationToken);
+        return rows
+            .Where(r => !string.IsNullOrWhiteSpace(r.Hash))
+            .Select(r => r.Hash)
+            .ToHashSet(StringComparer.Ordinal);
+    }
+
+    private async Task<Dictionary<string, RecordId>> LoadOplogRecordIdsByHashAsync(string datasetId,
+        CancellationToken cancellationToken)
+    {
+        var rows = await SelectAllAsync(datasetId, cancellationToken);
+        var records = new Dictionary<string, RecordId>(StringComparer.Ordinal);
+
+        foreach (var row in rows)
+        {
+            if (string.IsNullOrWhiteSpace(row.Hash)) continue;
+            records[row.Hash] = row.Id ?? SurrealStoreRecordIds.Oplog(row.Hash);
+        }
+
+        return records;
+    }
 }

src/ZB.MOM.WW.CBDDC.Persistence/Surreal/SurrealPeerOplogConfirmationStore.cs

@@ -10,6 +10,7 @@ namespace ZB.MOM.WW.CBDDC.Persistence.Surreal;
 public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
 {
     internal const string RegistrationSourceNodeId = "__peer_registration__";
+    private const string PrimaryDatasetId = DatasetId.Primary;
 
     private readonly ILogger<SurrealPeerOplogConfirmationStore> _logger;
     private readonly ICBDDCSurrealSchemaInitializer _schemaInitializer;
@@ -32,6 +33,19 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
         _logger = logger ?? NullLogger<SurrealPeerOplogConfirmationStore>.Instance;
     }
 
+    private static string NormalizeDatasetId(string? datasetId)
+    {
+        return DatasetId.Normalize(datasetId);
+    }
+
+    private static bool MatchesDataset(string? recordDatasetId, string datasetId)
+    {
+        if (string.IsNullOrWhiteSpace(recordDatasetId))
+            return string.Equals(datasetId, PrimaryDatasetId, StringComparison.Ordinal);
+
+        return string.Equals(NormalizeDatasetId(recordDatasetId), datasetId, StringComparison.Ordinal);
+    }
+
     /// <inheritdoc />
     public override async Task EnsurePeerRegisteredAsync(
         string peerNodeId,
@@ -39,16 +53,29 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
         PeerType type,
         CancellationToken cancellationToken = default)
     {
+        await EnsurePeerRegisteredAsync(peerNodeId, address, type, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task EnsurePeerRegisteredAsync(
+        string peerNodeId,
+        string address,
+        PeerType type,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         if (string.IsNullOrWhiteSpace(peerNodeId))
             throw new ArgumentException("Peer node id is required.", nameof(peerNodeId));
 
         var existing =
-            await FindByPairAsync(peerNodeId, RegistrationSourceNodeId, cancellationToken);
+            await FindByPairAsync(peerNodeId, RegistrationSourceNodeId, normalizedDatasetId, cancellationToken);
 
         if (existing == null)
         {
             var created = new PeerOplogConfirmation
             {
+                DatasetId = normalizedDatasetId,
                 PeerNodeId = peerNodeId,
                 SourceNodeId = RegistrationSourceNodeId,
                 ConfirmedWall = 0,
@@ -58,7 +85,9 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
                 IsActive = true
             };
 
-            await UpsertAsync(created, SurrealStoreRecordIds.PeerOplogConfirmation(peerNodeId, RegistrationSourceNodeId),
+            await UpsertAsync(
+                created,
+                SurrealStoreRecordIds.PeerOplogConfirmation(peerNodeId, RegistrationSourceNodeId, normalizedDatasetId),
                 cancellationToken);
 
             _logger.LogDebug("Registered peer confirmation tracking for {PeerNodeId} ({Address}, {Type}).", peerNodeId,
@@ -71,7 +100,8 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
         existing.IsActive = true;
         existing.LastConfirmedUtcMs = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();
         RecordId recordId =
-            existing.Id ?? SurrealStoreRecordIds.PeerOplogConfirmation(peerNodeId, RegistrationSourceNodeId);
+            existing.Id ??
+            SurrealStoreRecordIds.PeerOplogConfirmation(peerNodeId, RegistrationSourceNodeId, normalizedDatasetId);
         await UpsertAsync(existing, recordId, cancellationToken);
     }
 
@@ -83,19 +113,33 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
         string hash,
         CancellationToken cancellationToken = default)
     {
+        await UpdateConfirmationAsync(peerNodeId, sourceNodeId, timestamp, hash, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task UpdateConfirmationAsync(
+        string peerNodeId,
+        string sourceNodeId,
+        HlcTimestamp timestamp,
+        string hash,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         if (string.IsNullOrWhiteSpace(peerNodeId))
             throw new ArgumentException("Peer node id is required.", nameof(peerNodeId));
 
         if (string.IsNullOrWhiteSpace(sourceNodeId))
             throw new ArgumentException("Source node id is required.", nameof(sourceNodeId));
 
-        var existing = await FindByPairAsync(peerNodeId, sourceNodeId, cancellationToken);
+        var existing = await FindByPairAsync(peerNodeId, sourceNodeId, normalizedDatasetId, cancellationToken);
         long nowMs = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();
 
         if (existing == null)
         {
             var created = new PeerOplogConfirmation
             {
+                DatasetId = normalizedDatasetId,
                 PeerNodeId = peerNodeId,
                 SourceNodeId = sourceNodeId,
                 ConfirmedWall = timestamp.PhysicalTime,
@@ -104,7 +148,7 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
                 LastConfirmedUtc = DateTimeOffset.FromUnixTimeMilliseconds(nowMs),
                 IsActive = true
             };
-            await UpsertAsync(created, SurrealStoreRecordIds.PeerOplogConfirmation(peerNodeId, sourceNodeId),
+            await UpsertAsync(created, SurrealStoreRecordIds.PeerOplogConfirmation(peerNodeId, sourceNodeId, normalizedDatasetId),
                 cancellationToken);
             return;
         }
@@ -122,7 +166,7 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
         existing.LastConfirmedUtcMs = nowMs;
         existing.IsActive = true;
 
-        RecordId recordId = existing.Id ?? SurrealStoreRecordIds.PeerOplogConfirmation(peerNodeId, sourceNodeId);
+        RecordId recordId = existing.Id ?? SurrealStoreRecordIds.PeerOplogConfirmation(peerNodeId, sourceNodeId, normalizedDatasetId);
         await UpsertAsync(existing, recordId, cancellationToken);
     }
 
@@ -130,7 +174,15 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
     public override async Task<IEnumerable<PeerOplogConfirmation>> GetConfirmationsAsync(
         CancellationToken cancellationToken = default)
     {
-        var all = await SelectAllAsync(cancellationToken);
+        return await GetConfirmationsAsync(PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task<IEnumerable<PeerOplogConfirmation>> GetConfirmationsAsync(
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        var all = await SelectAllAsync(NormalizeDatasetId(datasetId), cancellationToken);
         return all
             .Where(c => !string.Equals(c.SourceNodeId, RegistrationSourceNodeId, StringComparison.Ordinal))
             .Select(c => c.ToDomain())
@@ -141,11 +193,20 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
     public override async Task<IEnumerable<PeerOplogConfirmation>> GetConfirmationsForPeerAsync(
         string peerNodeId,
         CancellationToken cancellationToken = default)
+    {
+        return await GetConfirmationsForPeerAsync(peerNodeId, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task<IEnumerable<PeerOplogConfirmation>> GetConfirmationsForPeerAsync(
+        string peerNodeId,
+        string datasetId,
+        CancellationToken cancellationToken = default)
     {
         if (string.IsNullOrWhiteSpace(peerNodeId))
             throw new ArgumentException("Peer node id is required.", nameof(peerNodeId));
 
-        var all = await SelectAllAsync(cancellationToken);
+        var all = await SelectAllAsync(NormalizeDatasetId(datasetId), cancellationToken);
         return all
             .Where(c => string.Equals(c.PeerNodeId, peerNodeId, StringComparison.Ordinal) &&
                         !string.Equals(c.SourceNodeId, RegistrationSourceNodeId, StringComparison.Ordinal))
@@ -156,10 +217,18 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
     /// <inheritdoc />
     public override async Task RemovePeerTrackingAsync(string peerNodeId, CancellationToken cancellationToken = default)
     {
+        await RemovePeerTrackingAsync(peerNodeId, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task RemovePeerTrackingAsync(string peerNodeId, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         if (string.IsNullOrWhiteSpace(peerNodeId))
             throw new ArgumentException("Peer node id is required.", nameof(peerNodeId));
 
-        var matches = (await SelectAllAsync(cancellationToken))
+        var matches = (await SelectAllAsync(normalizedDatasetId, cancellationToken))
             .Where(c => string.Equals(c.PeerNodeId, peerNodeId, StringComparison.Ordinal))
             .ToList();
 
@@ -173,7 +242,11 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
             match.IsActive = false;
             match.LastConfirmedUtcMs = nowMs;
 
-            RecordId recordId = match.Id ?? SurrealStoreRecordIds.PeerOplogConfirmation(match.PeerNodeId, match.SourceNodeId);
+            RecordId recordId = match.Id ??
+                                SurrealStoreRecordIds.PeerOplogConfirmation(
+                                    match.PeerNodeId,
+                                    match.SourceNodeId,
+                                    normalizedDatasetId);
             await UpsertAsync(match, recordId, cancellationToken);
         }
     }
@@ -182,7 +255,15 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
     public override async Task<IEnumerable<string>> GetActiveTrackedPeersAsync(
         CancellationToken cancellationToken = default)
     {
-        var all = await SelectAllAsync(cancellationToken);
+        return await GetActiveTrackedPeersAsync(PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task<IEnumerable<string>> GetActiveTrackedPeersAsync(
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        var all = await SelectAllAsync(NormalizeDatasetId(datasetId), cancellationToken);
         return all
             .Where(c => c.IsActive)
             .Select(c => c.PeerNodeId)
@@ -193,14 +274,45 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
     /// <inheritdoc />
     public override async Task DropAsync(CancellationToken cancellationToken = default)
     {
-        await EnsureReadyAsync(cancellationToken);
+        await DropAsync(PrimaryDatasetId, cancellationToken);
-        await _surrealClient.Delete(CBDDCSurrealSchemaNames.PeerOplogConfirmationsTable, cancellationToken);
+    }
+
+    /// <summary>
+    ///     Drops all peer confirmation rows for a dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    public async Task DropAsync(string datasetId, CancellationToken cancellationToken = default)
+    {
+        var rows = await SelectAllAsync(NormalizeDatasetId(datasetId), cancellationToken);
+        foreach (var row in rows)
+        {
+            RecordId recordId = row.Id ??
+                                SurrealStoreRecordIds.PeerOplogConfirmation(
+                                    row.PeerNodeId,
+                                    row.SourceNodeId,
+                                    NormalizeDatasetId(datasetId));
+            await _surrealClient.Delete(recordId, cancellationToken);
+        }
     }
 
     /// <inheritdoc />
     public override async Task<IEnumerable<PeerOplogConfirmation>> ExportAsync(CancellationToken cancellationToken = default)
     {
-        var all = await SelectAllAsync(cancellationToken);
+        var all = await SelectAllAsync(PrimaryDatasetId, cancellationToken);
+        return all.Select(c => c.ToDomain()).ToList();
+    }
+
+    /// <summary>
+    ///     Exports peer confirmations for a dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>The exported confirmations.</returns>
+    public async Task<IEnumerable<PeerOplogConfirmation>> ExportAsync(string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        var all = await SelectAllAsync(NormalizeDatasetId(datasetId), cancellationToken);
         return all.Select(c => c.ToDomain()).ToList();
     }
 
@@ -208,11 +320,25 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
     public override async Task ImportAsync(IEnumerable<PeerOplogConfirmation> items,
         CancellationToken cancellationToken = default)
     {
+        await ImportAsync(items, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <summary>
+    ///     Imports peer confirmation rows into a dataset.
+    /// </summary>
+    /// <param name="items">The confirmation items.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    public async Task ImportAsync(IEnumerable<PeerOplogConfirmation> items, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         foreach (var item in items)
         {
-            var existing = await FindByPairAsync(item.PeerNodeId, item.SourceNodeId, cancellationToken);
+            item.DatasetId = normalizedDatasetId;
+            var existing = await FindByPairAsync(item.PeerNodeId, item.SourceNodeId, normalizedDatasetId, cancellationToken);
             RecordId recordId =
-                existing?.Id ?? SurrealStoreRecordIds.PeerOplogConfirmation(item.PeerNodeId, item.SourceNodeId);
+                existing?.Id ?? SurrealStoreRecordIds.PeerOplogConfirmation(item.PeerNodeId, item.SourceNodeId, normalizedDatasetId);
             await UpsertAsync(item, recordId, cancellationToken);
         }
     }
@@ -221,12 +347,26 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
     public override async Task MergeAsync(IEnumerable<PeerOplogConfirmation> items,
         CancellationToken cancellationToken = default)
     {
+        await MergeAsync(items, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <summary>
+    ///     Merges peer confirmations into a dataset.
+    /// </summary>
+    /// <param name="items">The confirmation items.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    public async Task MergeAsync(IEnumerable<PeerOplogConfirmation> items, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         foreach (var item in items)
         {
-            var existing = await FindByPairAsync(item.PeerNodeId, item.SourceNodeId, cancellationToken);
+            item.DatasetId = normalizedDatasetId;
+            var existing = await FindByPairAsync(item.PeerNodeId, item.SourceNodeId, normalizedDatasetId, cancellationToken);
             if (existing == null)
             {
-                await UpsertAsync(item, SurrealStoreRecordIds.PeerOplogConfirmation(item.PeerNodeId, item.SourceNodeId),
+                await UpsertAsync(item, SurrealStoreRecordIds.PeerOplogConfirmation(item.PeerNodeId, item.SourceNodeId, normalizedDatasetId),
                     cancellationToken);
                 continue;
             }
@@ -259,7 +399,11 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
             if (!changed) continue;
 
             RecordId recordId =
-                existing.Id ?? SurrealStoreRecordIds.PeerOplogConfirmation(existing.PeerNodeId, existing.SourceNodeId);
+                existing.Id ??
+                SurrealStoreRecordIds.PeerOplogConfirmation(
+                    existing.PeerNodeId,
+                    existing.SourceNodeId,
+                    normalizedDatasetId);
             await UpsertAsync(existing, recordId, cancellationToken);
         }
     }
@@ -288,27 +432,37 @@ public class SurrealPeerOplogConfirmationStore : PeerOplogConfirmationStore
         await _schemaInitializer.EnsureInitializedAsync(cancellationToken);
     }
 
-    private async Task<List<SurrealPeerOplogConfirmationRecord>> SelectAllAsync(CancellationToken cancellationToken)
+    private async Task<List<SurrealPeerOplogConfirmationRecord>> SelectAllAsync(string datasetId,
+        CancellationToken cancellationToken)
     {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         await EnsureReadyAsync(cancellationToken);
         var rows = await _surrealClient.Select<SurrealPeerOplogConfirmationRecord>(
             CBDDCSurrealSchemaNames.PeerOplogConfirmationsTable,
             cancellationToken);
-        return rows?.ToList() ?? [];
+        return rows?
+                   .Where(row => MatchesDataset(row.DatasetId, normalizedDatasetId))
+                   .ToList()
+               ?? [];
     }
 
-    private async Task<SurrealPeerOplogConfirmationRecord?> FindByPairAsync(string peerNodeId, string sourceNodeId,
+    private async Task<SurrealPeerOplogConfirmationRecord?> FindByPairAsync(
+        string peerNodeId,
+        string sourceNodeId,
+        string datasetId,
         CancellationToken cancellationToken)
     {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         await EnsureReadyAsync(cancellationToken);
-        RecordId deterministicId = SurrealStoreRecordIds.PeerOplogConfirmation(peerNodeId, sourceNodeId);
+        RecordId deterministicId = SurrealStoreRecordIds.PeerOplogConfirmation(peerNodeId, sourceNodeId, normalizedDatasetId);
         var deterministic = await _surrealClient.Select<SurrealPeerOplogConfirmationRecord>(deterministicId, cancellationToken);
         if (deterministic != null &&
+            MatchesDataset(deterministic.DatasetId, normalizedDatasetId) &&
             string.Equals(deterministic.PeerNodeId, peerNodeId, StringComparison.Ordinal) &&
             string.Equals(deterministic.SourceNodeId, sourceNodeId, StringComparison.Ordinal))
             return deterministic;
 
-        var all = await SelectAllAsync(cancellationToken);
+        var all = await SelectAllAsync(normalizedDatasetId, cancellationToken);
         return all.FirstOrDefault(c =>
             string.Equals(c.PeerNodeId, peerNodeId, StringComparison.Ordinal) &&
             string.Equals(c.SourceNodeId, sourceNodeId, StringComparison.Ordinal));

src/ZB.MOM.WW.CBDDC.Persistence/Surreal/SurrealSnapshotMetadataStore.cs

@@ -8,6 +8,7 @@ namespace ZB.MOM.WW.CBDDC.Persistence.Surreal;
 
 public class SurrealSnapshotMetadataStore : SnapshotMetadataStore
 {
+    private const string PrimaryDatasetId = DatasetId.Primary;
     private readonly ILogger<SurrealSnapshotMetadataStore> _logger;
     private readonly ICBDDCSurrealSchemaInitializer _schemaInitializer;
     private readonly ISurrealDbClient _surrealClient;
@@ -29,17 +30,56 @@ public class SurrealSnapshotMetadataStore : SnapshotMetadataStore
         _logger = logger ?? NullLogger<SurrealSnapshotMetadataStore>.Instance;
     }
 
+    private static string NormalizeDatasetId(string? datasetId)
+    {
+        return DatasetId.Normalize(datasetId);
+    }
+
+    private static bool MatchesDataset(string? recordDatasetId, string datasetId)
+    {
+        if (string.IsNullOrWhiteSpace(recordDatasetId))
+            return string.Equals(datasetId, PrimaryDatasetId, StringComparison.Ordinal);
+
+        return string.Equals(NormalizeDatasetId(recordDatasetId), datasetId, StringComparison.Ordinal);
+    }
+
     /// <inheritdoc />
     public override async Task DropAsync(CancellationToken cancellationToken = default)
     {
-        await EnsureReadyAsync(cancellationToken);
+        await DropAsync(PrimaryDatasetId, cancellationToken);
-        await _surrealClient.Delete(CBDDCSurrealSchemaNames.SnapshotMetadataTable, cancellationToken);
+    }
+
+    /// <summary>
+    ///     Drops snapshot metadata rows for a dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    public async Task DropAsync(string datasetId, CancellationToken cancellationToken = default)
+    {
+        var rows = await SelectAllAsync(NormalizeDatasetId(datasetId), cancellationToken);
+        foreach (var row in rows)
+        {
+            RecordId recordId = row.Id ?? SurrealStoreRecordIds.SnapshotMetadata(row.NodeId, NormalizeDatasetId(datasetId));
+            await _surrealClient.Delete(recordId, cancellationToken);
+        }
     }
 
     /// <inheritdoc />
     public override async Task<IEnumerable<SnapshotMetadata>> ExportAsync(CancellationToken cancellationToken = default)
     {
-        var all = await SelectAllAsync(cancellationToken);
+        var all = await SelectAllAsync(PrimaryDatasetId, cancellationToken);
+        return all.Select(m => m.ToDomain()).ToList();
+    }
+
+    /// <summary>
+    ///     Exports snapshot metadata rows for a dataset.
+    /// </summary>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>Dataset-scoped snapshot metadata rows.</returns>
+    public async Task<IEnumerable<SnapshotMetadata>> ExportAsync(string datasetId, CancellationToken cancellationToken = default)
+    {
+        var all = await SelectAllAsync(NormalizeDatasetId(datasetId), cancellationToken);
         return all.Select(m => m.ToDomain()).ToList();
     }
 
@@ -47,14 +87,32 @@ public class SurrealSnapshotMetadataStore : SnapshotMetadataStore
     public override async Task<SnapshotMetadata?> GetSnapshotMetadataAsync(string nodeId,
         CancellationToken cancellationToken = default)
     {
-        var existing = await FindByNodeIdAsync(nodeId, cancellationToken);
+        var existing = await FindByNodeIdAsync(nodeId, PrimaryDatasetId, cancellationToken);
+        return existing?.ToDomain();
+    }
+
+    /// <inheritdoc />
+    public async Task<SnapshotMetadata?> GetSnapshotMetadataAsync(
+        string nodeId,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        var existing = await FindByNodeIdAsync(nodeId, NormalizeDatasetId(datasetId), cancellationToken);
         return existing?.ToDomain();
     }
 
     /// <inheritdoc />
     public override async Task<string?> GetSnapshotHashAsync(string nodeId, CancellationToken cancellationToken = default)
     {
-        var existing = await FindByNodeIdAsync(nodeId, cancellationToken);
+        var existing = await FindByNodeIdAsync(nodeId, PrimaryDatasetId, cancellationToken);
+        return existing?.Hash;
+    }
+
+    /// <inheritdoc />
+    public async Task<string?> GetSnapshotHashAsync(string nodeId, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        var existing = await FindByNodeIdAsync(nodeId, NormalizeDatasetId(datasetId), cancellationToken);
         return existing?.Hash;
     }
 
@@ -62,10 +120,24 @@ public class SurrealSnapshotMetadataStore : SnapshotMetadataStore
     public override async Task ImportAsync(IEnumerable<SnapshotMetadata> items,
         CancellationToken cancellationToken = default)
     {
+        await ImportAsync(items, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <summary>
+    ///     Imports snapshot metadata rows into a dataset.
+    /// </summary>
+    /// <param name="items">Snapshot metadata items.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    public async Task ImportAsync(IEnumerable<SnapshotMetadata> items, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         foreach (var item in items)
         {
-            var existing = await FindByNodeIdAsync(item.NodeId, cancellationToken);
+            item.DatasetId = normalizedDatasetId;
-            RecordId recordId = existing?.Id ?? SurrealStoreRecordIds.SnapshotMetadata(item.NodeId);
+            var existing = await FindByNodeIdAsync(item.NodeId, normalizedDatasetId, cancellationToken);
+            RecordId recordId = existing?.Id ?? SurrealStoreRecordIds.SnapshotMetadata(item.NodeId, normalizedDatasetId);
             await UpsertAsync(item, recordId, cancellationToken);
         }
     }
@@ -74,20 +146,45 @@ public class SurrealSnapshotMetadataStore : SnapshotMetadataStore
     public override async Task InsertSnapshotMetadataAsync(SnapshotMetadata metadata,
         CancellationToken cancellationToken = default)
     {
-        var existing = await FindByNodeIdAsync(metadata.NodeId, cancellationToken);
+        await InsertSnapshotMetadataAsync(metadata, PrimaryDatasetId, cancellationToken);
-        RecordId recordId = existing?.Id ?? SurrealStoreRecordIds.SnapshotMetadata(metadata.NodeId);
+    }
+
+    /// <inheritdoc />
+    public async Task InsertSnapshotMetadataAsync(
+        SnapshotMetadata metadata,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        metadata.DatasetId = normalizedDatasetId;
+        var existing = await FindByNodeIdAsync(metadata.NodeId, normalizedDatasetId, cancellationToken);
+        RecordId recordId = existing?.Id ?? SurrealStoreRecordIds.SnapshotMetadata(metadata.NodeId, normalizedDatasetId);
         await UpsertAsync(metadata, recordId, cancellationToken);
     }
 
     /// <inheritdoc />
     public override async Task MergeAsync(IEnumerable<SnapshotMetadata> items, CancellationToken cancellationToken = default)
     {
+        await MergeAsync(items, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <summary>
+    ///     Merges snapshot metadata rows into a dataset.
+    /// </summary>
+    /// <param name="items">Snapshot metadata items.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    public async Task MergeAsync(IEnumerable<SnapshotMetadata> items, string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         foreach (var metadata in items)
         {
-            var existing = await FindByNodeIdAsync(metadata.NodeId, cancellationToken);
+            metadata.DatasetId = normalizedDatasetId;
+            var existing = await FindByNodeIdAsync(metadata.NodeId, normalizedDatasetId, cancellationToken);
             if (existing == null)
             {
-                await UpsertAsync(metadata, SurrealStoreRecordIds.SnapshotMetadata(metadata.NodeId), cancellationToken);
+                await UpsertAsync(metadata, SurrealStoreRecordIds.SnapshotMetadata(metadata.NodeId, normalizedDatasetId), cancellationToken);
                 continue;
             }
 
@@ -96,7 +193,7 @@ public class SurrealSnapshotMetadataStore : SnapshotMetadataStore
                  metadata.TimestampLogicalCounter <= existing.TimestampLogicalCounter))
                 continue;
 
-            RecordId recordId = existing.Id ?? SurrealStoreRecordIds.SnapshotMetadata(metadata.NodeId);
+            RecordId recordId = existing.Id ?? SurrealStoreRecordIds.SnapshotMetadata(metadata.NodeId, normalizedDatasetId);
             await UpsertAsync(metadata, recordId, cancellationToken);
         }
     }
@@ -105,10 +202,21 @@ public class SurrealSnapshotMetadataStore : SnapshotMetadataStore
     public override async Task UpdateSnapshotMetadataAsync(SnapshotMetadata existingMeta,
         CancellationToken cancellationToken)
     {
-        var existing = await FindByNodeIdAsync(existingMeta.NodeId, cancellationToken);
+        await UpdateSnapshotMetadataAsync(existingMeta, PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task UpdateSnapshotMetadataAsync(
+        SnapshotMetadata existingMeta,
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
+        existingMeta.DatasetId = normalizedDatasetId;
+        var existing = await FindByNodeIdAsync(existingMeta.NodeId, normalizedDatasetId, cancellationToken);
         if (existing == null) return;
 
-        RecordId recordId = existing.Id ?? SurrealStoreRecordIds.SnapshotMetadata(existingMeta.NodeId);
+        RecordId recordId = existing.Id ?? SurrealStoreRecordIds.SnapshotMetadata(existingMeta.NodeId, normalizedDatasetId);
         await UpsertAsync(existingMeta, recordId, cancellationToken);
     }
 
@@ -116,7 +224,15 @@ public class SurrealSnapshotMetadataStore : SnapshotMetadataStore
     public override async Task<IEnumerable<SnapshotMetadata>> GetAllSnapshotMetadataAsync(
         CancellationToken cancellationToken = default)
     {
-        return await ExportAsync(cancellationToken);
+        return await ExportAsync(PrimaryDatasetId, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task<IEnumerable<SnapshotMetadata>> GetAllSnapshotMetadataAsync(
+        string datasetId,
+        CancellationToken cancellationToken = default)
+    {
+        return await ExportAsync(datasetId, cancellationToken);
     }
 
     private async Task UpsertAsync(SnapshotMetadata metadata, RecordId recordId, CancellationToken cancellationToken)
@@ -133,25 +249,33 @@ public class SurrealSnapshotMetadataStore : SnapshotMetadataStore
         await _schemaInitializer.EnsureInitializedAsync(cancellationToken);
     }
 
-    private async Task<List<SurrealSnapshotMetadataRecord>> SelectAllAsync(CancellationToken cancellationToken)
+    private async Task<List<SurrealSnapshotMetadataRecord>> SelectAllAsync(string datasetId,
+        CancellationToken cancellationToken)
     {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         await EnsureReadyAsync(cancellationToken);
         var rows = await _surrealClient.Select<SurrealSnapshotMetadataRecord>(
             CBDDCSurrealSchemaNames.SnapshotMetadataTable,
             cancellationToken);
-        return rows?.ToList() ?? [];
+        return rows?
+                   .Where(row => MatchesDataset(row.DatasetId, normalizedDatasetId))
+                   .ToList()
+               ?? [];
     }
 
-    private async Task<SurrealSnapshotMetadataRecord?> FindByNodeIdAsync(string nodeId, CancellationToken cancellationToken)
+    private async Task<SurrealSnapshotMetadataRecord?> FindByNodeIdAsync(string nodeId, string datasetId,
+        CancellationToken cancellationToken)
     {
+        string normalizedDatasetId = NormalizeDatasetId(datasetId);
         await EnsureReadyAsync(cancellationToken);
-        RecordId deterministicId = SurrealStoreRecordIds.SnapshotMetadata(nodeId);
+        RecordId deterministicId = SurrealStoreRecordIds.SnapshotMetadata(nodeId, normalizedDatasetId);
         var deterministic = await _surrealClient.Select<SurrealSnapshotMetadataRecord>(deterministicId, cancellationToken);
         if (deterministic != null &&
+            MatchesDataset(deterministic.DatasetId, normalizedDatasetId) &&
             string.Equals(deterministic.NodeId, nodeId, StringComparison.Ordinal))
             return deterministic;
 
-        var all = await SelectAllAsync(cancellationToken);
+        var all = await SelectAllAsync(normalizedDatasetId, cancellationToken);
         return all.FirstOrDefault(m => string.Equals(m.NodeId, nodeId, StringComparison.Ordinal));
     }
 }

src/ZB.MOM.WW.CBDDC.Persistence/Surreal/SurrealStoreRecords.cs

@@ -26,22 +26,28 @@ internal static class SurrealStoreRecordIds
     /// </summary>
     /// <param name="collection">The document collection name.</param>
     /// <param name="key">The document key.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
     /// <returns>The SurrealDB record identifier.</returns>
-    public static RecordId DocumentMetadata(string collection, string key)
+    public static RecordId DocumentMetadata(string collection, string key, string datasetId)
     {
+        string normalizedDatasetId = DatasetId.Normalize(datasetId);
         return RecordId.From(
             CBDDCSurrealSchemaNames.DocumentMetadataTable,
-            CompositeKey("docmeta", collection, key));
+            CompositeKey("docmeta", normalizedDatasetId, collection, key));
     }
 
     /// <summary>
     /// Creates the record identifier for snapshot metadata.
     /// </summary>
     /// <param name="nodeId">The node identifier.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
     /// <returns>The SurrealDB record identifier.</returns>
-    public static RecordId SnapshotMetadata(string nodeId)
+    public static RecordId SnapshotMetadata(string nodeId, string datasetId)
     {
-        return RecordId.From(CBDDCSurrealSchemaNames.SnapshotMetadataTable, nodeId);
+        string normalizedDatasetId = DatasetId.Normalize(datasetId);
+        return RecordId.From(
+            CBDDCSurrealSchemaNames.SnapshotMetadataTable,
+            CompositeKey("snapshotmeta", normalizedDatasetId, nodeId));
     }
 
     /// <summary>
@@ -59,12 +65,14 @@ internal static class SurrealStoreRecordIds
     /// </summary>
     /// <param name="peerNodeId">The peer node identifier.</param>
     /// <param name="sourceNodeId">The source node identifier.</param>
+    /// <param name="datasetId">The dataset identifier.</param>
     /// <returns>The SurrealDB record identifier.</returns>
-    public static RecordId PeerOplogConfirmation(string peerNodeId, string sourceNodeId)
+    public static RecordId PeerOplogConfirmation(string peerNodeId, string sourceNodeId, string datasetId)
     {
+        string normalizedDatasetId = DatasetId.Normalize(datasetId);
         return RecordId.From(
             CBDDCSurrealSchemaNames.PeerOplogConfirmationsTable,
-            CompositeKey("peerconfirm", peerNodeId, sourceNodeId));
+            CompositeKey("peerconfirm", normalizedDatasetId, peerNodeId, sourceNodeId));
     }
 
     private static string CompositeKey(string prefix, string first, string second)
@@ -72,10 +80,22 @@ internal static class SurrealStoreRecordIds
         byte[] bytes = Encoding.UTF8.GetBytes($"{prefix}\n{first}\n{second}");
         return Convert.ToHexString(SHA256.HashData(bytes)).ToLowerInvariant();
     }
+
+    private static string CompositeKey(string prefix, string first, string second, string third)
+    {
+        byte[] bytes = Encoding.UTF8.GetBytes($"{prefix}\n{first}\n{second}\n{third}");
+        return Convert.ToHexString(SHA256.HashData(bytes)).ToLowerInvariant();
+    }
 }
 
 internal sealed class SurrealOplogRecord : Record
 {
+    /// <summary>
+    /// Gets or sets the dataset identifier.
+    /// </summary>
+    [JsonPropertyName("datasetId")]
+    public string DatasetId { get; set; } = "";
+
     /// <summary>
     /// Gets or sets the collection name.
     /// </summary>
@@ -133,6 +153,12 @@ internal sealed class SurrealOplogRecord : Record
 
 internal sealed class SurrealDocumentMetadataRecord : Record
 {
+    /// <summary>
+    /// Gets or sets the dataset identifier.
+    /// </summary>
+    [JsonPropertyName("datasetId")]
+    public string DatasetId { get; set; } = "";
+
     /// <summary>
     /// Gets or sets the collection name.
     /// </summary>
@@ -205,6 +231,12 @@ internal sealed class SurrealRemotePeerRecord : Record
 
 internal sealed class SurrealPeerOplogConfirmationRecord : Record
 {
+    /// <summary>
+    /// Gets or sets the dataset identifier.
+    /// </summary>
+    [JsonPropertyName("datasetId")]
+    public string DatasetId { get; set; } = "";
+
     /// <summary>
     /// Gets or sets the peer node identifier.
     /// </summary>
@@ -250,6 +282,12 @@ internal sealed class SurrealPeerOplogConfirmationRecord : Record
 
 internal sealed class SurrealSnapshotMetadataRecord : Record
 {
+    /// <summary>
+    /// Gets or sets the dataset identifier.
+    /// </summary>
+    [JsonPropertyName("datasetId")]
+    public string DatasetId { get; set; } = "";
+
     /// <summary>
     /// Gets or sets the node identifier.
     /// </summary>
@@ -286,6 +324,7 @@ internal static class SurrealStoreRecordMappers
     {
         return new SurrealOplogRecord
         {
+            DatasetId = DatasetId.Normalize(entry.DatasetId),
             Collection = entry.Collection,
             Key = entry.Key,
             Operation = (int)entry.Operation,
@@ -316,7 +355,8 @@ internal static class SurrealStoreRecordMappers
             payload,
             new HlcTimestamp(record.TimestampPhysicalTime, record.TimestampLogicalCounter, record.TimestampNodeId),
             record.PreviousHash,
-            record.Hash);
+            record.Hash,
+            record.DatasetId);
     }
 
     /// <summary>
@@ -328,6 +368,7 @@ internal static class SurrealStoreRecordMappers
     {
         return new SurrealDocumentMetadataRecord
         {
+            DatasetId = DatasetId.Normalize(metadata.DatasetId),
             Collection = metadata.Collection,
             Key = metadata.Key,
             HlcPhysicalTime = metadata.UpdatedAt.PhysicalTime,
@@ -348,7 +389,8 @@ internal static class SurrealStoreRecordMappers
             record.Collection,
             record.Key,
             new HlcTimestamp(record.HlcPhysicalTime, record.HlcLogicalCounter, record.HlcNodeId),
-            record.IsDeleted);
+            record.IsDeleted,
+            record.DatasetId);
     }
 
     /// <summary>
@@ -401,6 +443,7 @@ internal static class SurrealStoreRecordMappers
     {
         return new SurrealPeerOplogConfirmationRecord
         {
+            DatasetId = DatasetId.Normalize(confirmation.DatasetId),
             PeerNodeId = confirmation.PeerNodeId,
             SourceNodeId = confirmation.SourceNodeId,
             ConfirmedWall = confirmation.ConfirmedWall,
@@ -420,6 +463,7 @@ internal static class SurrealStoreRecordMappers
     {
         return new PeerOplogConfirmation
         {
+            DatasetId = DatasetId.Normalize(record.DatasetId),
             PeerNodeId = record.PeerNodeId,
             SourceNodeId = record.SourceNodeId,
             ConfirmedWall = record.ConfirmedWall,
@@ -439,6 +483,7 @@ internal static class SurrealStoreRecordMappers
     {
         return new SurrealSnapshotMetadataRecord
         {
+            DatasetId = DatasetId.Normalize(metadata.DatasetId),
             NodeId = metadata.NodeId,
             TimestampPhysicalTime = metadata.TimestampPhysicalTime,
             TimestampLogicalCounter = metadata.TimestampLogicalCounter,
@@ -455,6 +500,7 @@ internal static class SurrealStoreRecordMappers
     {
         return new SnapshotMetadata
         {
+            DatasetId = DatasetId.Normalize(record.DatasetId),
             NodeId = record.NodeId,
             TimestampPhysicalTime = record.TimestampPhysicalTime,
             TimestampLogicalCounter = record.TimestampLogicalCounter,

tests/ZB.MOM.WW.CBDDC.Core.Tests/DatasetAwareModelTests.cs

@@ -0,0 +1,43 @@
+using System.Text.Json;
+using ZB.MOM.WW.CBDDC.Core.Storage;
+
+namespace ZB.MOM.WW.CBDDC.Core.Tests;
+
+public class DatasetAwareModelTests
+{
+    [Fact]
+    public void DocumentMetadata_ShouldDefaultDatasetId_ToPrimary()
+    {
+        var metadata = new DocumentMetadata("Users", "42", new HlcTimestamp(100, 0, "node"));
+
+        metadata.DatasetId.ShouldBe(DatasetId.Primary);
+    }
+
+    [Fact]
+    public void DocumentMetadata_SerializationRoundTrip_ShouldPreserveDatasetId()
+    {
+        var original = new DocumentMetadata("Users", "42", new HlcTimestamp(100, 0, "node"), false, "logs");
+
+        string json = JsonSerializer.Serialize(original);
+        var restored = JsonSerializer.Deserialize<DocumentMetadata>(json);
+
+        restored.ShouldNotBeNull();
+        restored.DatasetId.ShouldBe("logs");
+    }
+
+    [Fact]
+    public void SnapshotMetadata_ShouldDefaultDatasetId_ToPrimary()
+    {
+        var metadata = new SnapshotMetadata();
+
+        metadata.DatasetId.ShouldBe(DatasetId.Primary);
+    }
+
+    [Fact]
+    public void PeerOplogConfirmation_ShouldDefaultDatasetId_ToPrimary()
+    {
+        var confirmation = new PeerOplogConfirmation();
+
+        confirmation.DatasetId.ShouldBe(DatasetId.Primary);
+    }
+}

tests/ZB.MOM.WW.CBDDC.Core.Tests/OplogEntryTests.cs

@@ -70,4 +70,28 @@ public class OplogEntryTests
 
         entry.IsValid().ShouldBeTrue();
     }
+
+    /// <summary>
+    ///     Verifies that entries default to the primary dataset when dataset is omitted.
+    /// </summary>
+    [Fact]
+    public void Constructor_ShouldDefaultDatasetId_ToPrimary()
+    {
+        var entry = new OplogEntry("col", "key", OperationType.Put, null, new HlcTimestamp(1, 0, "node"), "prev");
+
+        entry.DatasetId.ShouldBe(DatasetId.Primary);
+    }
+
+    /// <summary>
+    ///     Verifies that hash computation includes dataset identity to prevent cross-dataset collisions.
+    /// </summary>
+    [Fact]
+    public void ComputeHash_ShouldDiffer_WhenDatasetDiffers()
+    {
+        var timestamp = new HlcTimestamp(100, 0, "node-1");
+        var primary = new OplogEntry("col", "key", OperationType.Put, null, timestamp, "prev", datasetId: "primary");
+        var logs = new OplogEntry("col", "key", OperationType.Put, null, timestamp, "prev", datasetId: "logs");
+
+        logs.Hash.ShouldNotBe(primary.Hash);
+    }
 }

tests/ZB.MOM.WW.CBDDC.Network.Tests/MultiDatasetRegistrationTests.cs

@@ -0,0 +1,47 @@
+using Microsoft.Extensions.DependencyInjection;
+using ZB.MOM.WW.CBDDC.Core.Network;
+using ZB.MOM.WW.CBDDC.Core.Storage;
+
+namespace ZB.MOM.WW.CBDDC.Network.Tests;
+
+public class MultiDatasetRegistrationTests
+{
+    [Fact]
+    public void AddCBDDCMultiDataset_ShouldRegisterCoordinatorAndReplaceSyncOrchestrator()
+    {
+        var services = new ServiceCollection();
+
+        services.AddCBDDCNetwork<TestPeerNodeConfigurationProvider>(useHostedService: false);
+        services.AddCBDDCMultiDataset(options =>
+        {
+            options.EnableMultiDatasetSync = true;
+            options.EnableDatasetPrimary = true;
+            options.EnableDatasetLogs = true;
+            options.EnableDatasetTimeseries = true;
+        });
+
+        services.Any(descriptor => descriptor.ServiceType == typeof(IMultiDatasetSyncOrchestrator)).ShouldBeTrue();
+
+        var syncDescriptor = services.Last(descriptor => descriptor.ServiceType == typeof(ISyncOrchestrator));
+        syncDescriptor.ImplementationFactory.ShouldNotBeNull();
+    }
+
+    private sealed class TestPeerNodeConfigurationProvider : IPeerNodeConfigurationProvider
+    {
+        public event PeerNodeConfigurationChangedEventHandler? ConfigurationChanged
+        {
+            add { }
+            remove { }
+        }
+
+        public Task<PeerNodeConfiguration> GetConfiguration()
+        {
+            return Task.FromResult(new PeerNodeConfiguration
+            {
+                NodeId = "node-test",
+                TcpPort = 9000,
+                AuthToken = "auth"
+            });
+        }
+    }
+}

tests/ZB.MOM.WW.CBDDC.Network.Tests/MultiDatasetSyncOrchestratorTests.cs

@@ -0,0 +1,102 @@
+using Microsoft.Extensions.Logging.Abstractions;
+using ZB.MOM.WW.CBDDC.Core;
+using ZB.MOM.WW.CBDDC.Core.Network;
+using ZB.MOM.WW.CBDDC.Core.Storage;
+
+namespace ZB.MOM.WW.CBDDC.Network.Tests;
+
+public class MultiDatasetSyncOrchestratorTests
+{
+    [Fact]
+    public void Constructor_WhenMultiDatasetDisabled_ShouldOnlyCreatePrimaryContext()
+    {
+        var sut = CreateSut(
+            [
+                new DatasetSyncOptions { DatasetId = DatasetId.Primary, Enabled = true },
+                new DatasetSyncOptions { DatasetId = DatasetId.Logs, Enabled = true }
+            ],
+            new MultiDatasetRuntimeOptions
+            {
+                EnableMultiDatasetSync = false,
+                EnableDatasetPrimary = true,
+                EnableDatasetLogs = true
+            });
+
+        var datasetIds = sut.Contexts.Select(c => c.DatasetId).ToList();
+        datasetIds.Count.ShouldBe(1);
+        datasetIds[0].ShouldBe(DatasetId.Primary);
+    }
+
+    [Fact]
+    public async Task StartStop_WhenOneDatasetThrows_ShouldContinueOtherDatasets()
+    {
+        var orchestrators = new Dictionary<string, TrackingSyncOrchestrator>(StringComparer.Ordinal)
+        {
+            [DatasetId.Primary] = new TrackingSyncOrchestrator(),
+            [DatasetId.Logs] = new TrackingSyncOrchestrator(startException: new InvalidOperationException("boom")),
+            [DatasetId.Timeseries] = new TrackingSyncOrchestrator()
+        };
+
+        var sut = CreateSut(
+            [],
+            new MultiDatasetRuntimeOptions
+            {
+                EnableMultiDatasetSync = true,
+                EnableDatasetPrimary = true,
+                EnableDatasetLogs = true,
+                EnableDatasetTimeseries = true
+            },
+            options => orchestrators[DatasetId.Normalize(options.DatasetId)]);
+
+        await sut.Start();
+        await sut.Stop();
+
+        orchestrators[DatasetId.Primary].StartCalls.ShouldBe(1);
+        orchestrators[DatasetId.Primary].StopCalls.ShouldBe(1);
+
+        orchestrators[DatasetId.Logs].StartCalls.ShouldBe(1);
+        orchestrators[DatasetId.Logs].StopCalls.ShouldBe(1);
+
+        orchestrators[DatasetId.Timeseries].StartCalls.ShouldBe(1);
+        orchestrators[DatasetId.Timeseries].StopCalls.ShouldBe(1);
+    }
+
+    private static MultiDatasetSyncOrchestrator CreateSut(
+        IEnumerable<DatasetSyncOptions> datasetOptions,
+        MultiDatasetRuntimeOptions runtimeOptions,
+        Func<DatasetSyncOptions, ISyncOrchestrator>? orchestratorFactory = null)
+    {
+        return new MultiDatasetSyncOrchestrator(
+            Substitute.For<IDiscoveryService>(),
+            Substitute.For<IOplogStore>(),
+            Substitute.For<IDocumentStore>(),
+            Substitute.For<ISnapshotMetadataStore>(),
+            Substitute.For<ISnapshotService>(),
+            Substitute.For<IPeerNodeConfigurationProvider>(),
+            NullLoggerFactory.Instance,
+            datasetOptions,
+            runtimeOptions,
+            orchestratorFactory: orchestratorFactory);
+    }
+
+    private sealed class TrackingSyncOrchestrator(Exception? startException = null, Exception? stopException = null)
+        : ISyncOrchestrator
+    {
+        public int StartCalls { get; private set; }
+        public int StopCalls { get; private set; }
+
+        public Task Start()
+        {
+            StartCalls++;
+            if (startException != null) throw startException;
+            return Task.CompletedTask;
+        }
+
+        public Task Stop()
+        {
+            StopCalls++;
+            if (stopException != null) throw stopException;
+            return Task.CompletedTask;
+        }
+    }
+}

tests/ZB.MOM.WW.CBDDC.Network.Tests/ProtocolTests.cs

@@ -1,4 +1,6 @@
 using Microsoft.Extensions.Logging.Abstractions;
+using Google.Protobuf;
+using ZB.MOM.WW.CBDDC.Core;
 using ZB.MOM.WW.CBDDC.Network.Proto;
 using ZB.MOM.WW.CBDDC.Network.Protocol;
 using ZB.MOM.WW.CBDDC.Network.Security;
@@ -145,6 +147,44 @@ public class ProtocolTests
         decoded.NodeId.ShouldBe("fragmented");
     }
 
+    /// <summary>
+    ///     Verifies that dataset-aware protocol fields are serialized and parsed correctly.
+    /// </summary>
+    [Fact]
+    public void DatasetAwareMessages_ShouldRoundTripDatasetFields()
+    {
+        var request = new PullChangesRequest
+        {
+            SinceWall = 10,
+            SinceLogic = 1,
+            SinceNode = "node-a",
+            DatasetId = "logs"
+        };
+
+        byte[] payload = request.ToByteArray();
+        var decoded = PullChangesRequest.Parser.ParseFrom(payload);
+
+        decoded.DatasetId.ShouldBe("logs");
+    }
+
+    /// <summary>
+    ///     Verifies that legacy messages with no dataset id default to the primary dataset.
+    /// </summary>
+    [Fact]
+    public void DatasetAwareMessages_WhenMissingDataset_ShouldDefaultToPrimary()
+    {
+        var legacy = new HandshakeRequest
+        {
+            NodeId = "node-legacy",
+            AuthToken = "token"
+        };
+
+        byte[] payload = legacy.ToByteArray();
+        var decoded = HandshakeRequest.Parser.ParseFrom(payload);
+
+        DatasetId.Normalize(decoded.DatasetId).ShouldBe(DatasetId.Primary);
+    }
+
     // Helper Stream for fragmentation test
     private class FragmentedMemoryStream : MemoryStream
     {

tests/ZB.MOM.WW.CBDDC.Network.Tests/SnapshotReconnectRegressionTests.cs

@@ -16,6 +16,8 @@ public class SnapshotReconnectRegressionTests
             .Returns((SnapshotMetadata?)null);
         snapshotMetadataStore.GetSnapshotHashAsync(Arg.Any<string>(), Arg.Any<CancellationToken>())
             .Returns((string?)null);
+        snapshotMetadataStore.GetSnapshotHashAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns((string?)null);
         snapshotMetadataStore.GetAllSnapshotMetadataAsync(Arg.Any<CancellationToken>())
             .Returns(Array.Empty<SnapshotMetadata>());
         return snapshotMetadataStore;
@@ -30,6 +32,10 @@ public class SnapshotReconnectRegressionTests
             .Returns(Task.CompletedTask);
         snapshotService.MergeSnapshotAsync(Arg.Any<Stream>(), Arg.Any<CancellationToken>())
             .Returns(Task.CompletedTask);
+        snapshotService.ReplaceDatabaseAsync(Arg.Any<Stream>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns(Task.CompletedTask);
+        snapshotService.MergeSnapshotAsync(Arg.Any<Stream>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns(Task.CompletedTask);
         return snapshotService;
     }
 
@@ -69,8 +75,12 @@ public class SnapshotReconnectRegressionTests
         var oplogStore = Substitute.For<IOplogStore>();
         oplogStore.GetLastEntryHashAsync(Arg.Any<string>(), Arg.Any<CancellationToken>())
             .Returns(localHeadHash);
+        oplogStore.GetLastEntryHashAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns(localHeadHash);
         oplogStore.ApplyBatchAsync(Arg.Any<IEnumerable<OplogEntry>>(), Arg.Any<CancellationToken>())
             .Returns(Task.CompletedTask);
+        oplogStore.ApplyBatchAsync(Arg.Any<IEnumerable<OplogEntry>>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns(Task.CompletedTask);
         return oplogStore;
     }
 
@@ -84,6 +94,8 @@ public class SnapshotReconnectRegressionTests
             null);
         client.GetChainRangeAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
             .Returns(_ => Task.FromException<List<OplogEntry>>(new SnapshotRequiredException()));
+        client.GetChainRangeAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns(_ => Task.FromException<List<OplogEntry>>(new SnapshotRequiredException()));
         return client;
     }
 
@@ -109,19 +121,38 @@ public class SnapshotReconnectRegressionTests
         store.EnsurePeerRegisteredAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<PeerType>(),
                 Arg.Any<CancellationToken>())
             .Returns(Task.CompletedTask);
+        store.EnsurePeerRegisteredAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<PeerType>(), Arg.Any<string>(),
+                Arg.Any<CancellationToken>())
+            .Returns(Task.CompletedTask);
         store.UpdateConfirmationAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<HlcTimestamp>(), Arg.Any<string>(),
                 Arg.Any<CancellationToken>())
             .Returns(Task.CompletedTask);
+        store.UpdateConfirmationAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<HlcTimestamp>(), Arg.Any<string>(),
+                Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns(Task.CompletedTask);
         store.GetConfirmationsAsync(Arg.Any<CancellationToken>()).Returns(Array.Empty<PeerOplogConfirmation>());
+        store.GetConfirmationsAsync(Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns(Array.Empty<PeerOplogConfirmation>());
         store.GetConfirmationsForPeerAsync(Arg.Any<string>(), Arg.Any<CancellationToken>())
             .Returns(Array.Empty<PeerOplogConfirmation>());
+        store.GetConfirmationsForPeerAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns(Array.Empty<PeerOplogConfirmation>());
         store.RemovePeerTrackingAsync(Arg.Any<string>(), Arg.Any<CancellationToken>()).Returns(Task.CompletedTask);
+        store.RemovePeerTrackingAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns(Task.CompletedTask);
         store.GetActiveTrackedPeersAsync(Arg.Any<CancellationToken>()).Returns(Array.Empty<string>());
+        store.GetActiveTrackedPeersAsync(Arg.Any<string>(), Arg.Any<CancellationToken>()).Returns(Array.Empty<string>());
         store.ExportAsync(Arg.Any<CancellationToken>()).Returns(Array.Empty<PeerOplogConfirmation>());
+        store.ExportAsync(Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns(Array.Empty<PeerOplogConfirmation>());
         store.ImportAsync(Arg.Any<IEnumerable<PeerOplogConfirmation>>(), Arg.Any<CancellationToken>())
             .Returns(Task.CompletedTask);
+        store.ImportAsync(Arg.Any<IEnumerable<PeerOplogConfirmation>>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns(Task.CompletedTask);
         store.MergeAsync(Arg.Any<IEnumerable<PeerOplogConfirmation>>(), Arg.Any<CancellationToken>())
             .Returns(Task.CompletedTask);
+        store.MergeAsync(Arg.Any<IEnumerable<PeerOplogConfirmation>>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns(Task.CompletedTask);
         return store;
     }
 
@@ -136,6 +167,8 @@ public class SnapshotReconnectRegressionTests
         var snapshotMetadataStore = CreateSnapshotMetadataStore();
         snapshotMetadataStore.GetSnapshotHashAsync(Arg.Any<string>(), Arg.Any<CancellationToken>())
             .Returns("snapshot-boundary-hash");
+        snapshotMetadataStore.GetSnapshotHashAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns("snapshot-boundary-hash");
         var snapshotService = CreateSnapshotService();
 
         var orch = new TestableSyncOrchestrator(
@@ -165,7 +198,7 @@ public class SnapshotReconnectRegressionTests
         // Assert
         result.ShouldBe("Success");
         await client.DidNotReceive()
-            .GetChainRangeAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>());
+            .GetChainRangeAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>());
     }
 
     /// <summary>
@@ -179,6 +212,8 @@ public class SnapshotReconnectRegressionTests
         var snapshotMetadataStore = CreateSnapshotMetadataStore();
         snapshotMetadataStore.GetSnapshotHashAsync(Arg.Any<string>(), Arg.Any<CancellationToken>())
             .Returns("snapshot-boundary-hash");
+        snapshotMetadataStore.GetSnapshotHashAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+            .Returns("snapshot-boundary-hash");
         var snapshotService = CreateSnapshotService();
 
         var orch = new TestableSyncOrchestrator(
@@ -208,7 +243,11 @@ public class SnapshotReconnectRegressionTests
         await Should.ThrowAsync<SnapshotRequiredException>(async () =>
             await orch.TestProcessInboundBatchAsync(client, "remote-node", entries, CancellationToken.None));
 
-        await client.Received(1).GetChainRangeAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>());
+        await client.Received(1).GetChainRangeAsync(
+            Arg.Any<string>(),
+            Arg.Any<string>(),
+            Arg.Any<string>(),
+            Arg.Any<CancellationToken>());
     }
 
     // Subclass to expose private method

tests/ZB.MOM.WW.CBDDC.Network.Tests/SyncOrchestratorConfirmationTests.cs

@@ -39,18 +39,21 @@ public class SyncOrchestratorConfirmationTests
             "peer-a",
             "10.0.0.1:9000",
             PeerType.LanDiscovered,
+            DatasetId.Primary,
             Arg.Any<CancellationToken>());
 
         await confirmationStore.Received(1).EnsurePeerRegisteredAsync(
             "peer-b",
             "10.0.0.2:9010",
             PeerType.StaticRemote,
+            DatasetId.Primary,
             Arg.Any<CancellationToken>());
 
         await confirmationStore.DidNotReceive().EnsurePeerRegisteredAsync(
             "local",
             Arg.Any<string>(),
             Arg.Any<PeerType>(),
+            Arg.Any<string>(),
             Arg.Any<CancellationToken>());
     }
 
@@ -89,6 +92,7 @@ public class SyncOrchestratorConfirmationTests
             "peer-new",
             "10.0.0.25:9010",
             PeerType.LanDiscovered,
+            DatasetId.Primary,
             Arg.Any<CancellationToken>());
     }
 
@@ -114,9 +118,9 @@ public class SyncOrchestratorConfirmationTests
         remote.SetTimestamp("node-behind", new HlcTimestamp(299, 9, "node-behind"));
         remote.SetTimestamp("node-remote-only", new HlcTimestamp(900, 0, "node-remote-only"));
 
-        oplogStore.GetLastEntryHashAsync("node-equal", Arg.Any<CancellationToken>())
+        oplogStore.GetLastEntryHashAsync("node-equal", DatasetId.Primary, Arg.Any<CancellationToken>())
             .Returns("hash-equal");
-        oplogStore.GetLastEntryHashAsync("node-ahead", Arg.Any<CancellationToken>())
+        oplogStore.GetLastEntryHashAsync("node-ahead", DatasetId.Primary, Arg.Any<CancellationToken>())
             .Returns((string?)null);
 
         await orchestrator.AdvanceConfirmationsFromVectorClockAsync("peer-1", local, remote, CancellationToken.None);
@@ -126,6 +130,7 @@ public class SyncOrchestratorConfirmationTests
             "node-equal",
             new HlcTimestamp(100, 1, "node-equal"),
             "hash-equal",
+            DatasetId.Primary,
             Arg.Any<CancellationToken>());
 
         await confirmationStore.Received(1).UpdateConfirmationAsync(
@@ -133,6 +138,7 @@ public class SyncOrchestratorConfirmationTests
             "node-ahead",
             new HlcTimestamp(200, 0, "node-ahead"),
             string.Empty,
+            DatasetId.Primary,
             Arg.Any<CancellationToken>());
 
         await confirmationStore.DidNotReceive().UpdateConfirmationAsync(
@@ -140,6 +146,7 @@ public class SyncOrchestratorConfirmationTests
             "node-behind",
             Arg.Any<HlcTimestamp>(),
             Arg.Any<string>(),
+            Arg.Any<string>(),
             Arg.Any<CancellationToken>());
 
         await confirmationStore.DidNotReceive().UpdateConfirmationAsync(
@@ -147,6 +154,7 @@ public class SyncOrchestratorConfirmationTests
             "node-local-only",
             Arg.Any<HlcTimestamp>(),
             Arg.Any<string>(),
+            Arg.Any<string>(),
             Arg.Any<CancellationToken>());
 
         await confirmationStore.DidNotReceive().UpdateConfirmationAsync(
@@ -154,6 +162,7 @@ public class SyncOrchestratorConfirmationTests
             "node-remote-only",
             Arg.Any<HlcTimestamp>(),
             Arg.Any<string>(),
+            Arg.Any<string>(),
             Arg.Any<CancellationToken>());
     }
 
@@ -182,6 +191,7 @@ public class SyncOrchestratorConfirmationTests
             "source-1",
             new HlcTimestamp(120, 1, "source-1"),
             "hash-120",
+            DatasetId.Primary,
             Arg.Any<CancellationToken>());
     }
 
@@ -206,6 +216,7 @@ public class SyncOrchestratorConfirmationTests
             Arg.Any<string>(),
             Arg.Any<HlcTimestamp>(),
             Arg.Any<string>(),
+            Arg.Any<string>(),
             Arg.Any<CancellationToken>());
     }
 

tests/ZB.MOM.WW.CBDDC.Network.Tests/SyncOrchestratorMaintenancePruningTests.cs

@@ -138,7 +138,10 @@ public class SyncOrchestratorMaintenancePruningTests
 
         await orchestrator.RunMaintenanceIfDueAsync(config, DateTime.UtcNow, CancellationToken.None);
 
-        await oplogStore.DidNotReceive().PruneOplogAsync(Arg.Any<HlcTimestamp>(), Arg.Any<CancellationToken>());
+        await oplogStore.DidNotReceive().PruneOplogAsync(
+            Arg.Any<HlcTimestamp>(),
+            Arg.Any<string>(),
+            Arg.Any<CancellationToken>());
     }
 
     /// <summary>
@@ -187,6 +190,7 @@ public class SyncOrchestratorMaintenancePruningTests
                 timestamp.PhysicalTime == 100 &&
                 timestamp.LogicalCounter == 0 &&
                 string.Equals(timestamp.NodeId, "node-local", StringComparison.Ordinal)),
+            DatasetId.Primary,
             Arg.Any<CancellationToken>());
     }
 
@@ -228,7 +232,10 @@ public class SyncOrchestratorMaintenancePruningTests
 
         var now = DateTime.UtcNow;
         await orchestrator.RunMaintenanceIfDueAsync(config, now, CancellationToken.None);
-        await oplogStore.DidNotReceive().PruneOplogAsync(Arg.Any<HlcTimestamp>(), Arg.Any<CancellationToken>());
+        await oplogStore.DidNotReceive().PruneOplogAsync(
+            Arg.Any<HlcTimestamp>(),
+            Arg.Any<string>(),
+            Arg.Any<CancellationToken>());
 
         await orchestrator.RunMaintenanceIfDueAsync(config, now.AddMinutes(2), CancellationToken.None);
 
@@ -237,6 +244,7 @@ public class SyncOrchestratorMaintenancePruningTests
                 timestamp.PhysicalTime == 100 &&
                 timestamp.LogicalCounter == 0 &&
                 string.Equals(timestamp.NodeId, "node-local", StringComparison.Ordinal)),
+            DatasetId.Primary,
             Arg.Any<CancellationToken>());
     }
 

tests/ZB.MOM.WW.CBDDC.Sample.Console.Tests/MultiDatasetConfigParsingTests.cs

@@ -0,0 +1,38 @@
+using System.Text;
+using Microsoft.Extensions.Configuration;
+using ZB.MOM.WW.CBDDC.Network;
+
+namespace ZB.MOM.WW.CBDDC.Sample.Console.Tests;
+
+public class MultiDatasetConfigParsingTests
+{
+    [Fact]
+    public void MultiDatasetSection_ShouldBindRuntimeOptions()
+    {
+        const string json = """
+                            {
+                              "CBDDC": {
+                                "MultiDataset": {
+                                  "EnableMultiDatasetSync": true,
+                                  "EnableDatasetPrimary": true,
+                                  "EnableDatasetLogs": true,
+                                  "EnableDatasetTimeseries": false
+                                }
+                              }
+                            }
+                            """;
+
+        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(json));
+        var config = new ConfigurationBuilder()
+            .AddJsonStream(stream)
+            .Build();
+
+        var options = config.GetSection("CBDDC:MultiDataset").Get<MultiDatasetRuntimeOptions>();
+
+        options.ShouldNotBeNull();
+        options.EnableMultiDatasetSync.ShouldBeTrue();
+        options.EnableDatasetPrimary.ShouldBeTrue();
+        options.EnableDatasetLogs.ShouldBeTrue();
+        options.EnableDatasetTimeseries.ShouldBeFalse();
+    }
+}

tests/ZB.MOM.WW.CBDDC.Sample.Console.Tests/SurrealStoreContractTests.cs

@@ -54,6 +54,68 @@ public class SurrealOplogStoreContractTests
         (await store.ExportAsync()).ShouldBeEmpty();
     }
 
+    /// <summary>
+    ///     Verifies oplog reads and writes are isolated by dataset identifier.
+    /// </summary>
+    [Fact]
+    public async Task OplogStore_DatasetIsolation_Works()
+    {
+        await using var harness = new SurrealTestHarness();
+        var store = harness.CreateOplogStore();
+
+        var primaryEntry = CreateOplogEntry("Users", "p1", "node-a", 100, 0, "");
+        var logsEntry = CreateOplogEntry("Users", "l1", "node-a", 100, 1, "");
+
+        await store.AppendOplogEntryAsync(primaryEntry, DatasetId.Primary);
+        await store.AppendOplogEntryAsync(logsEntry, DatasetId.Logs);
+
+        var primary = (await store.ExportAsync(DatasetId.Primary)).ToList();
+        var logs = (await store.ExportAsync(DatasetId.Logs)).ToList();
+
+        primary.Count.ShouldBe(1);
+        primary[0].DatasetId.ShouldBe(DatasetId.Primary);
+
+        logs.Count.ShouldBe(1);
+        logs[0].DatasetId.ShouldBe(DatasetId.Logs);
+    }
+
+    /// <summary>
+    ///     Verifies legacy oplog rows without dataset id are treated as primary dataset.
+    /// </summary>
+    [Fact]
+    public async Task OplogStore_LegacyRowsWithoutDatasetId_MapToPrimaryOnly()
+    {
+        await using var harness = new SurrealTestHarness();
+        var store = harness.CreateOplogStore();
+
+        await harness.SurrealEmbeddedClient.InitializeAsync();
+        await harness.SurrealEmbeddedClient.RawQueryAsync(
+            """
+            UPSERT type::thing($table, $id) CONTENT {
+                collection: "Users",
+                key: "legacy",
+                operation: 0,
+                payloadJson: "{}",
+                timestampPhysicalTime: 10,
+                timestampLogicalCounter: 0,
+                timestampNodeId: "node-legacy",
+                hash: "legacy-hash",
+                previousHash: ""
+            };
+            """,
+            new Dictionary<string, object?>
+            {
+                ["table"] = CBDDCSurrealSchemaNames.OplogEntriesTable,
+                ["id"] = "legacy-hash"
+            });
+
+        var primary = (await store.GetOplogAfterAsync(new HlcTimestamp(0, 0, ""), DatasetId.Primary)).ToList();
+        var logs = (await store.GetOplogAfterAsync(new HlcTimestamp(0, 0, ""), DatasetId.Logs)).ToList();
+
+        primary.Any(entry => entry.Hash == "legacy-hash").ShouldBeTrue();
+        logs.Any(entry => entry.Hash == "legacy-hash").ShouldBeFalse();
+    }
+
     private static OplogEntry CreateOplogEntry(
         string collection,
         string key,
@@ -110,6 +172,34 @@ public class SurrealDocumentMetadataStoreContractTests
         var exported = (await store.ExportAsync()).ToList();
         exported.Count.ShouldBe(3);
     }
+
+    /// <summary>
+    ///     Verifies document metadata records do not leak across datasets.
+    /// </summary>
+    [Fact]
+    public async Task DocumentMetadataStore_DatasetIsolation_Works()
+    {
+        await using var harness = new SurrealTestHarness();
+        var store = harness.CreateDocumentMetadataStore();
+
+        await store.UpsertMetadataAsync(
+            new DocumentMetadata("Users", "doc-shared", new HlcTimestamp(100, 0, "node-a"), false, DatasetId.Primary),
+            DatasetId.Primary);
+        await store.UpsertMetadataAsync(
+            new DocumentMetadata("Users", "doc-shared", new HlcTimestamp(101, 0, "node-a"), false, DatasetId.Logs),
+            DatasetId.Logs);
+
+        var primary = await store.GetMetadataAsync("Users", "doc-shared", DatasetId.Primary);
+        var logs = await store.GetMetadataAsync("Users", "doc-shared", DatasetId.Logs);
+
+        primary.ShouldNotBeNull();
+        primary.DatasetId.ShouldBe(DatasetId.Primary);
+        primary.UpdatedAt.ShouldBe(new HlcTimestamp(100, 0, "node-a"));
+
+        logs.ShouldNotBeNull();
+        logs.DatasetId.ShouldBe(DatasetId.Logs);
+        logs.UpdatedAt.ShouldBe(new HlcTimestamp(101, 0, "node-a"));
+    }
 }
 
 public class SurrealPeerConfigurationStoreContractTests
@@ -206,6 +296,42 @@ public class SurrealPeerOplogConfirmationStoreContractTests
         afterDeactivate.All(x => x.IsActive == false).ShouldBeTrue();
     }
 
+    /// <summary>
+    ///     Verifies peer confirmations are isolated by dataset.
+    /// </summary>
+    [Fact]
+    public async Task PeerOplogConfirmationStore_DatasetIsolation_Works()
+    {
+        await using var harness = new SurrealTestHarness();
+        var store = harness.CreatePeerOplogConfirmationStore();
+
+        await store.EnsurePeerRegisteredAsync("peer-a", "10.0.0.10:5050", PeerType.StaticRemote, DatasetId.Primary);
+        await store.EnsurePeerRegisteredAsync("peer-a", "10.0.0.10:5050", PeerType.StaticRemote, DatasetId.Logs);
+        await store.UpdateConfirmationAsync(
+            "peer-a",
+            "source-1",
+            new HlcTimestamp(100, 1, "source-1"),
+            "hash-primary",
+            DatasetId.Primary);
+        await store.UpdateConfirmationAsync(
+            "peer-a",
+            "source-1",
+            new HlcTimestamp(200, 1, "source-1"),
+            "hash-logs",
+            DatasetId.Logs);
+
+        var primary = (await store.GetConfirmationsForPeerAsync("peer-a", DatasetId.Primary)).ToList();
+        var logs = (await store.GetConfirmationsForPeerAsync("peer-a", DatasetId.Logs)).ToList();
+
+        primary.Count.ShouldBe(1);
+        primary[0].ConfirmedHash.ShouldBe("hash-primary");
+        primary[0].DatasetId.ShouldBe(DatasetId.Primary);
+
+        logs.Count.ShouldBe(1);
+        logs[0].ConfirmedHash.ShouldBe("hash-logs");
+        logs[0].DatasetId.ShouldBe(DatasetId.Logs);
+    }
+
     /// <summary>
     ///     Verifies merge semantics prefer newer confirmations and preserve active-state transitions.
     /// </summary>
@@ -343,6 +469,45 @@ public class SurrealSnapshotMetadataStoreContractTests
         all[0].NodeId.ShouldBe("node-a");
         all[1].NodeId.ShouldBe("node-b");
     }
+
+    /// <summary>
+    ///     Verifies snapshot metadata rows are isolated by dataset.
+    /// </summary>
+    [Fact]
+    public async Task SnapshotMetadataStore_DatasetIsolation_Works()
+    {
+        await using var harness = new SurrealTestHarness();
+        var store = harness.CreateSnapshotMetadataStore();
+
+        await store.InsertSnapshotMetadataAsync(new SnapshotMetadata
+        {
+            DatasetId = DatasetId.Primary,
+            NodeId = "node-a",
+            TimestampPhysicalTime = 100,
+            TimestampLogicalCounter = 0,
+            Hash = "hash-primary"
+        }, DatasetId.Primary);
+
+        await store.InsertSnapshotMetadataAsync(new SnapshotMetadata
+        {
+            DatasetId = DatasetId.Logs,
+            NodeId = "node-a",
+            TimestampPhysicalTime = 200,
+            TimestampLogicalCounter = 0,
+            Hash = "hash-logs"
+        }, DatasetId.Logs);
+
+        var primary = await store.GetSnapshotMetadataAsync("node-a", DatasetId.Primary);
+        var logs = await store.GetSnapshotMetadataAsync("node-a", DatasetId.Logs);
+
+        primary.ShouldNotBeNull();
+        primary.Hash.ShouldBe("hash-primary");
+        primary.DatasetId.ShouldBe(DatasetId.Primary);
+
+        logs.ShouldNotBeNull();
+        logs.Hash.ShouldBe("hash-logs");
+        logs.DatasetId.ShouldBe(DatasetId.Logs);
+    }
 }
 
 internal sealed class SurrealTestHarness : IAsyncDisposable
@@ -431,6 +596,11 @@ internal sealed class SurrealTestHarness : IAsyncDisposable
             NullLogger<SurrealSnapshotMetadataStore>.Instance);
     }
 
+    /// <summary>
+    ///     Gets the embedded Surreal client used by this harness.
+    /// </summary>
+    public ICBDDCSurrealEmbeddedClient SurrealEmbeddedClient => _client;
+
     /// <inheritdoc />
     public async ValueTask DisposeAsync()
     {

tests/ZB.MOM.WW.CDBBC.E2E.Benchmark.Tests/BenchmarkPeerNode.cs

@@ -113,12 +113,7 @@ internal sealed class BenchmarkPeerNode : IAsyncDisposable
 
     public async Task UpsertUserAsync(User user)
     {
-        User? existing = Context.Users.Find(u => u.Id == user.Id).FirstOrDefault();
-        if (existing == null)
-            await Context.Users.InsertAsync(user);
-        else
         await Context.Users.UpdateAsync(user);
-
         await Context.SaveChangesAsync();
     }
 
@@ -127,6 +122,11 @@ internal sealed class BenchmarkPeerNode : IAsyncDisposable
         return Context.Users.Find(u => u.Id == userId).Any();
     }
 
+    public int CountUsersWithPrefix(string prefix)
+    {
+        return Context.Users.FindAll().Count(u => u.Id.StartsWith(prefix, StringComparison.Ordinal));
+    }
+
     public async ValueTask DisposeAsync()
     {
         try

tests/ZB.MOM.WW.CDBBC.E2E.Benchmark.Tests/OfflineResyncThroughputBenchmarks.cs

@@ -0,0 +1,142 @@
+using BenchmarkDotNet.Attributes;
+using System.Net;
+using System.Net.Sockets;
+using ZB.MOM.WW.CBDDC.Core.Network;
+using ZB.MOM.WW.CBDDC.Sample.Console;
+
+namespace ZB.MOM.WW.CDBBC.E2E.Benchmark.Tests;
+
+[MemoryDiagnoser]
+[SimpleJob(launchCount: 1, warmupCount: 0, iterationCount: 1)]
+public class OfflineResyncThroughputBenchmarks
+{
+    private const int BacklogOperationCount = 10_000;
+    private BenchmarkPeerNode _onlineNode = null!;
+    private BenchmarkPeerNode _offlineNode = null!;
+    private int _runSequence;
+    private string _currentPrefix = string.Empty;
+
+    [GlobalSetup]
+    public Task GlobalSetupAsync()
+    {
+        return Task.CompletedTask;
+    }
+
+    [GlobalCleanup]
+    public Task GlobalCleanupAsync()
+    {
+        // Avoid explicit node disposal in BenchmarkDotNet child processes due Surreal embedded callback race.
+        // Process teardown releases resources after benchmark completion.
+        return Task.CompletedTask;
+    }
+
+    [IterationSetup(Target = nameof(OfflineBacklogWriteThroughput100k))]
+    public void SetupOfflineWriteThroughput()
+    {
+        _currentPrefix = $"offline-write-{Interlocked.Increment(ref _runSequence):D6}";
+        InitializeIterationNodesAsync().GetAwaiter().GetResult();
+    }
+
+    [Benchmark(Description = "Offline backlog write throughput (10K ops)", OperationsPerInvoke = BacklogOperationCount)]
+    public async Task OfflineBacklogWriteThroughput100k()
+    {
+        await WriteBatchAsync(_currentPrefix, BacklogOperationCount);
+    }
+
+    [IterationSetup(Target = nameof(OfflineNodeResyncDurationAfter100kBacklog))]
+    public void SetupOfflineResyncBenchmark()
+    {
+        _currentPrefix = $"offline-resync-{Interlocked.Increment(ref _runSequence):D6}";
+        InitializeIterationNodesAsync().GetAwaiter().GetResult();
+        WriteBatchAsync(_currentPrefix, BacklogOperationCount).GetAwaiter().GetResult();
+    }
+
+    [Benchmark(Description = "Offline node re-sync duration after 10K backlog")]
+    public async Task OfflineNodeResyncDurationAfter100kBacklog()
+    {
+        await _offlineNode.StartAsync();
+        await WaitForReplicationAsync(_currentPrefix, BacklogOperationCount, TimeSpan.FromMinutes(3));
+    }
+
+    private async Task WriteBatchAsync(string prefix, int count)
+    {
+        for (var i = 0; i < count; i++)
+        {
+            string userId = $"{prefix}-{i:D6}";
+            await _onlineNode.UpsertUserAsync(CreateUser(userId));
+        }
+    }
+
+    private async Task WaitForReplicationAsync(string prefix, int expectedCount, TimeSpan timeout)
+    {
+        DateTime deadline = DateTime.UtcNow.Add(timeout);
+        while (DateTime.UtcNow < deadline)
+        {
+            if (_offlineNode.CountUsersWithPrefix(prefix) >= expectedCount)
+                return;
+
+            await Task.Delay(250);
+        }
+
+        int replicatedCount = _offlineNode.CountUsersWithPrefix(prefix);
+        throw new TimeoutException(
+            $"Timed out waiting for re-sync. Expected {expectedCount}, replicated {replicatedCount}.");
+    }
+
+    private static User CreateUser(string userId)
+    {
+        return new User
+        {
+            Id = userId,
+            Name = $"user-{userId}",
+            Age = 30,
+            Address = new Address { City = "OfflineBenchmarkCity" }
+        };
+    }
+
+    private static int GetAvailableTcpPort()
+    {
+        using var listener = new TcpListener(IPAddress.Loopback, 0);
+        listener.Start();
+        return ((IPEndPoint)listener.LocalEndpoint).Port;
+    }
+
+    private async Task InitializeIterationNodesAsync()
+    {
+        int onlinePort = GetAvailableTcpPort();
+        int offlinePort = GetAvailableTcpPort();
+        while (offlinePort == onlinePort)
+            offlinePort = GetAvailableTcpPort();
+
+        string clusterToken = Guid.NewGuid().ToString("N");
+
+        _onlineNode = BenchmarkPeerNode.Create(
+            "offline-benchmark-online",
+            onlinePort,
+            clusterToken,
+            [
+                new KnownPeerConfiguration
+                {
+                    NodeId = "offline-benchmark-offline",
+                    Host = "127.0.0.1",
+                    Port = offlinePort
+                }
+            ]);
+
+        _offlineNode = BenchmarkPeerNode.Create(
+            "offline-benchmark-offline",
+            offlinePort,
+            clusterToken,
+            [
+                new KnownPeerConfiguration
+                {
+                    NodeId = "offline-benchmark-online",
+                    Host = "127.0.0.1",
+                    Port = onlinePort
+                }
+            ]);
+
+        await _onlineNode.StartAsync();
+        await Task.Delay(250);
+    }
+}

tests/ZB.MOM.WW.CDBBC.E2E.Benchmark.Tests/SerilogLogEntry.cs

@@ -0,0 +1,50 @@
+using System;
+using System.Collections.Generic;
+
+namespace ZB.MOM.WW.CDBBC.E2E.Benchmark.Tests;
+
+/// <summary>
+///     Represents a typical Serilog log entry.
+/// </summary>
+public sealed class SerilogLogEntry
+{
+    /// <summary>
+    ///     Timestamp when the log event was written.
+    /// </summary>
+    public DateTimeOffset Timestamp { get; set; }
+
+    /// <summary>
+    ///     Log level (for example: Information, Warning, Error).
+    /// </summary>
+    public string Level { get; set; } = "Information";
+
+    /// <summary>
+    ///     Name of the logger/category (typically the class name).
+    /// </summary>
+    public string? LoggerName { get; set; }
+
+    /// <summary>
+    ///     Correlation context identifier used to tie log entries to a request.
+    /// </summary>
+    public string? ContextId { get; set; }
+
+    /// <summary>
+    ///     Original message template used by Serilog.
+    /// </summary>
+    public string MessageTemplate { get; set; } = string.Empty;
+
+    /// <summary>
+    ///     Fully rendered message text.
+    /// </summary>
+    public string? RenderedMessage { get; set; }
+
+    /// <summary>
+    ///     Exception details if one was logged.
+    /// </summary>
+    public string? Exception { get; set; }
+
+    /// <summary>
+    ///     Structured context values captured from Serilog context.
+    /// </summary>
+    public Dictionary<string, object?> ContextProperties { get; set; } = new(StringComparer.Ordinal);
+}

tests/ZB.MOM.WW.CDBBC.E2E.Benchmark.Tests/SurrealLogStorageBenchmarks.cs

@@ -0,0 +1,440 @@
+using System.Diagnostics;
+using System.Text;
+using BenchmarkDotNet.Attributes;
+using SurrealDb.Net.Models;
+using SurrealDb.Net.Models.Response;
+using ZB.MOM.WW.CBDDC.Persistence.Surreal;
+
+namespace ZB.MOM.WW.CDBBC.E2E.Benchmark.Tests;
+
+[MemoryDiagnoser]
+[SimpleJob(launchCount: 1, warmupCount: 1, iterationCount: 3)]
+public class SurrealLogStorageBenchmarks
+{
+    private const int LogRecordCount = 100_000;
+    private const int InsertBatchSize = 500;
+    private const string LogTable = "benchmark_log_entry";
+    private const string LogKvTable = "benchmark_log_kv";
+
+    private static readonly string[] LoggerNames =
+    [
+        "Api.RequestHandler",
+        "Api.AuthController",
+        "Api.OrderController",
+        "Api.InventoryController",
+        "Api.CustomerController",
+        "Workers.OutboxPublisher",
+        "Workers.NotificationDispatcher",
+        "Infrastructure.SqlRepository",
+        "Infrastructure.CacheService",
+        "Infrastructure.HttpClient",
+        "Domain.OrderService",
+        "Domain.PricingService"
+    ];
+
+    private static readonly string[] TenantIds =
+    [
+        "tenant-01",
+        "tenant-02",
+        "tenant-03",
+        "tenant-04",
+        "tenant-05",
+        "tenant-06",
+        "tenant-07",
+        "tenant-08"
+    ];
+
+    private CBDDCSurrealEmbeddedClient _surrealClient = null!;
+    private string _databasePath = string.Empty;
+    private string _workDir = string.Empty;
+    private DateTime _seedBaseUtc;
+    private DateTime _queryRangeStartUtc;
+    private DateTime _queryRangeEndUtc;
+    private string _contextIdQueryValue = string.Empty;
+    private string _loggerQueryValue = string.Empty;
+    private string _contextStringKeyQueryValue = string.Empty;
+    private string _contextStringValueQueryValue = string.Empty;
+    private string _contextNumericKeyQueryValue = string.Empty;
+    private int _contextNumericValueQueryValue;
+
+    [GlobalSetup]
+    public async Task GlobalSetupAsync()
+    {
+        _workDir = Path.Combine(Path.GetTempPath(), $"cbddc-serilog-benchmark-{Guid.NewGuid():N}");
+        Directory.CreateDirectory(_workDir);
+        _databasePath = Path.Combine(_workDir, "serilog.rocksdb");
+
+        _surrealClient = new CBDDCSurrealEmbeddedClient(
+            new CBDDCSurrealEmbeddedOptions
+            {
+                Endpoint = "rocksdb://local",
+                DatabasePath = _databasePath,
+                Namespace = "cbddc_benchmark",
+                Database = $"serilog_{Guid.NewGuid():N}",
+                Cdc = new CBDDCSurrealCdcOptions { Enabled = false }
+            });
+
+        await _surrealClient.InitializeAsync();
+        await DefineSchemaAndIndexesAsync();
+
+        _seedBaseUtc = DateTime.UtcNow.AddDays(-1);
+        _contextIdQueryValue = BuildContextId(LogRecordCount / 2);
+        _loggerQueryValue = LoggerNames[3];
+        _contextStringKeyQueryValue = "tenantId";
+        _contextStringValueQueryValue = TenantIds[5];
+        _contextNumericKeyQueryValue = "statusCode";
+        _contextNumericValueQueryValue = 500;
+        _queryRangeStartUtc = _seedBaseUtc.AddMinutes(6);
+        _queryRangeEndUtc = _queryRangeStartUtc.AddSeconds(30);
+
+        var seedTimer = Stopwatch.StartNew();
+        await InsertLogRecordsAsync();
+        seedTimer.Stop();
+
+        long sizeBytes = CalculatePathSizeBytes(_databasePath);
+        Console.WriteLine(
+            $"Seeded {LogRecordCount:N0} records in {seedTimer.Elapsed.TotalSeconds:F2}s. " +
+            $"RocksDB size: {sizeBytes / (1024d * 1024d):F2} MiB ({sizeBytes:N0} bytes). Path: {_databasePath}");
+    }
+
+    [GlobalCleanup]
+    public Task GlobalCleanupAsync()
+    {
+        // Avoid explicit Surreal embedded disposal in benchmark child processes due known native callback race.
+        return Task.CompletedTask;
+    }
+
+    [Benchmark(Description = "Query by contextId (latest 200 rows)")]
+    public async Task QueryByContextIdAsync()
+    {
+        await ExecuteQueryAsync(
+            $"""
+             SELECT * FROM {LogTable}
+             WHERE contextId = $contextId
+             ORDER BY timestamp DESC
+             LIMIT 200;
+             """,
+            new Dictionary<string, object?> { ["contextId"] = _contextIdQueryValue });
+    }
+
+    [Benchmark(Description = "Query by loggerName + timestamp range (latest 200 rows)")]
+    public async Task QueryByLoggerAndTimestampAsync()
+    {
+        await ExecuteQueryAsync(
+            $"""
+             SELECT * FROM {LogTable}
+             WHERE loggerName = $loggerName
+               AND timestamp >= $fromTs
+               AND timestamp <= $toTs
+             ORDER BY timestamp DESC
+             LIMIT 200;
+             """,
+            new Dictionary<string, object?>
+            {
+                ["loggerName"] = _loggerQueryValue,
+                ["fromTs"] = _queryRangeStartUtc,
+                ["toTs"] = _queryRangeEndUtc
+            });
+    }
+
+    [Benchmark(Description = "Query by loggerName + timestamp + arbitrary context string key/value")]
+    public async Task QueryByLoggerTimestampAndContextKeyAsync()
+    {
+        await ExecuteQueryAsync(
+            $"""
+             LET $logIds = (
+               SELECT VALUE logId FROM {LogKvTable}
+               WHERE loggerName = $loggerName
+                 AND key = $contextKey
+                 AND valueStr = $contextValueStr
+                 AND timestamp >= $fromTs
+                 AND timestamp <= $toTs
+               ORDER BY timestamp DESC
+               LIMIT 200
+             );
+             SELECT * FROM {LogTable}
+             WHERE id INSIDE $logIds
+             ORDER BY timestamp DESC
+             LIMIT 200;
+             """,
+            new Dictionary<string, object?>
+            {
+                ["loggerName"] = _loggerQueryValue,
+                ["fromTs"] = _queryRangeStartUtc,
+                ["toTs"] = _queryRangeEndUtc,
+                ["contextKey"] = _contextStringKeyQueryValue,
+                ["contextValueStr"] = _contextStringValueQueryValue
+            });
+    }
+
+    [Benchmark(Description = "Query by loggerName + timestamp + arbitrary context number key/value")]
+    public async Task QueryByLoggerTimestampAndNumericContextKeyAsync()
+    {
+        await ExecuteQueryAsync(
+            $"""
+             LET $logIds = (
+               SELECT VALUE logId FROM {LogKvTable}
+               WHERE loggerName = $loggerName
+                 AND key = $contextKey
+                 AND valueNum = $contextValueNum
+                 AND timestamp >= $fromTs
+                 AND timestamp <= $toTs
+               ORDER BY timestamp DESC
+               LIMIT 200
+             );
+             SELECT * FROM {LogTable}
+             WHERE id INSIDE $logIds
+             ORDER BY timestamp DESC
+             LIMIT 200;
+             """,
+            new Dictionary<string, object?>
+            {
+                ["loggerName"] = _loggerQueryValue,
+                ["fromTs"] = _queryRangeStartUtc,
+                ["toTs"] = _queryRangeEndUtc,
+                ["contextKey"] = _contextNumericKeyQueryValue,
+                ["contextValueNum"] = _contextNumericValueQueryValue
+            });
+    }
+
+    [Benchmark(Description = "RocksDB size (bytes)")]
+    public long GetDatabaseFileSizeBytes()
+    {
+        return CalculatePathSizeBytes(_databasePath);
+    }
+
+    private async Task DefineSchemaAndIndexesAsync()
+    {
+        string schemaSql =
+            $"""
+             DEFINE TABLE OVERWRITE {LogTable} SCHEMAFULL;
+             DEFINE FIELD OVERWRITE timestamp ON TABLE {LogTable} TYPE datetime;
+             DEFINE FIELD OVERWRITE level ON TABLE {LogTable} TYPE string;
+             DEFINE FIELD OVERWRITE loggerName ON TABLE {LogTable} TYPE option<string>;
+             DEFINE FIELD OVERWRITE contextId ON TABLE {LogTable} TYPE option<string>;
+             DEFINE FIELD OVERWRITE messageTemplate ON TABLE {LogTable} TYPE string;
+             DEFINE FIELD OVERWRITE renderedMessage ON TABLE {LogTable} TYPE option<string>;
+             DEFINE FIELD OVERWRITE exception ON TABLE {LogTable} TYPE option<string>;
+             DEFINE FIELD OVERWRITE contextValues ON TABLE {LogTable} TYPE object FLEXIBLE;
+
+             DEFINE INDEX OVERWRITE idx_log_contextid_ts
+             ON TABLE {LogTable} COLUMNS contextId, timestamp;
+
+             DEFINE INDEX OVERWRITE idx_log_logger_ts
+             ON TABLE {LogTable} COLUMNS loggerName, timestamp;
+
+             DEFINE TABLE OVERWRITE {LogKvTable} SCHEMAFULL;
+             DEFINE FIELD OVERWRITE logId ON TABLE {LogKvTable} TYPE record<{LogTable}>;
+             DEFINE FIELD OVERWRITE loggerName ON TABLE {LogKvTable} TYPE string;
+             DEFINE FIELD OVERWRITE timestamp ON TABLE {LogKvTable} TYPE datetime;
+             DEFINE FIELD OVERWRITE key ON TABLE {LogKvTable} TYPE string;
+             DEFINE FIELD OVERWRITE valueStr ON TABLE {LogKvTable} TYPE option<string>;
+             DEFINE FIELD OVERWRITE valueNum ON TABLE {LogKvTable} TYPE option<number>;
+             DEFINE FIELD OVERWRITE valueBool ON TABLE {LogKvTable} TYPE option<bool>;
+
+             DEFINE INDEX OVERWRITE idx_logkv_logger_key_str_ts
+             ON TABLE {LogKvTable} COLUMNS loggerName, key, valueStr, timestamp;
+
+             DEFINE INDEX OVERWRITE idx_logkv_logger_key_num_ts
+             ON TABLE {LogKvTable} COLUMNS loggerName, key, valueNum, timestamp;
+
+             DEFINE INDEX OVERWRITE idx_logkv_logger_key_bool_ts
+             ON TABLE {LogKvTable} COLUMNS loggerName, key, valueBool, timestamp;
+
+             DEFINE INDEX OVERWRITE idx_logkv_logid
+             ON TABLE {LogKvTable} COLUMNS logId;
+             """;
+
+        var response = await _surrealClient.RawQueryAsync(schemaSql);
+        EnsureSuccessfulResponse(response, "Schema definition");
+    }
+
+    private async Task InsertLogRecordsAsync()
+    {
+        for (var batchStart = 0; batchStart < LogRecordCount; batchStart += InsertBatchSize)
+        {
+            int batchCount = Math.Min(InsertBatchSize, LogRecordCount - batchStart);
+            var sqlBuilder = new StringBuilder();
+            sqlBuilder.AppendLine("BEGIN TRANSACTION;");
+
+            var parameters = new Dictionary<string, object?>(batchCount * 2);
+            for (var offset = 0; offset < batchCount; offset++)
+            {
+                int sequence = batchStart + offset;
+                string idParameterName = $"id{offset}";
+                string recordParameterName = $"record{offset}";
+                string logId = $"log-{sequence:D8}";
+                RecordId logRecordId = RecordId.From(LogTable, logId);
+                IReadOnlyDictionary<string, object?> logRecord = CreateLogRecord(sequence);
+
+                parameters[idParameterName] = logRecordId;
+                parameters[recordParameterName] = logRecord;
+                sqlBuilder.Append("UPSERT $")
+                    .Append(idParameterName)
+                    .Append(" CONTENT $")
+                    .Append(recordParameterName)
+                    .AppendLine(";");
+
+                int kvOrdinal = 0;
+                foreach (IReadOnlyDictionary<string, object?> kvRow in CreateKvRows(logId, logRecordId, logRecord))
+                {
+                    string kvIdParameterName = $"kvid{offset}_{kvOrdinal}";
+                    string kvRecordParameterName = $"kvrecord{offset}_{kvOrdinal}";
+                    parameters[kvIdParameterName] = RecordId.From(LogKvTable, $"{logId}-{kvOrdinal:D2}");
+                    parameters[kvRecordParameterName] = kvRow;
+
+                    sqlBuilder.Append("UPSERT $")
+                        .Append(kvIdParameterName)
+                        .Append(" CONTENT $")
+                        .Append(kvRecordParameterName)
+                        .AppendLine(";");
+
+                    kvOrdinal++;
+                }
+            }
+
+            sqlBuilder.AppendLine("COMMIT TRANSACTION;");
+
+            var response = await _surrealClient.RawQueryAsync(sqlBuilder.ToString(), parameters);
+            EnsureSuccessfulResponse(response, $"Insert batch starting at row {batchStart}");
+        }
+    }
+
+    private IReadOnlyDictionary<string, object?> CreateLogRecord(int sequence)
+    {
+        DateTime timestamp = _seedBaseUtc.AddMilliseconds(sequence * 10L);
+        string loggerName = LoggerNames[sequence % LoggerNames.Length];
+        string tenantId = TenantIds[sequence % TenantIds.Length];
+        bool isBackground = sequence % 7 == 0;
+        string? exception = sequence % 2_500 == 0
+            ? "System.InvalidOperationException: simulated benchmark exception."
+            : null;
+
+        var record = new Dictionary<string, object?>
+        {
+            ["timestamp"] = timestamp,
+            ["level"] = ResolveLogLevel(sequence),
+            ["loggerName"] = loggerName,
+            ["contextId"] = BuildContextId(sequence),
+            ["messageTemplate"] = "Processed request {RequestId} for {Route}",
+            ["renderedMessage"] = $"Processed request req-{sequence:D8} for /api/items/{sequence % 250}",
+            ["contextValues"] = new Dictionary<string, object?>
+            {
+                ["tenantId"] = tenantId,
+                ["requestId"] = $"req-{sequence:D8}",
+                ["route"] = $"/api/items/{sequence % 250}",
+                ["statusCode"] = sequence % 20 == 0 ? 500 : 200,
+                ["elapsedMs"] = 5 + (sequence % 200),
+                ["nodeId"] = $"node-{sequence % 8:D2}",
+                ["isBackground"] = isBackground
+            }
+        };
+
+        if (!string.IsNullOrEmpty(exception))
+            record["exception"] = exception;
+
+        return record;
+    }
+
+    private static IEnumerable<IReadOnlyDictionary<string, object?>> CreateKvRows(
+        string logId,
+        RecordId logRecordId,
+        IReadOnlyDictionary<string, object?> logRecord)
+    {
+        if (!logRecord.TryGetValue("loggerName", out object? loggerNameValue) || loggerNameValue is not string loggerName)
+            yield break;
+        if (!logRecord.TryGetValue("timestamp", out object? timestampValue) || timestampValue is not DateTime timestamp)
+            yield break;
+        if (!logRecord.TryGetValue("contextValues", out object? contextValuesObject) ||
+            contextValuesObject is not IReadOnlyDictionary<string, object?> contextValues)
+            yield break;
+
+        foreach ((string key, object? value) in contextValues)
+        {
+            if (value == null) continue;
+
+            var row = new Dictionary<string, object?>
+            {
+                ["logId"] = logRecordId,
+                ["loggerName"] = loggerName,
+                ["timestamp"] = timestamp,
+                ["key"] = key
+            };
+
+            switch (value)
+            {
+                case string stringValue:
+                    row["valueStr"] = stringValue;
+                    break;
+                case bool boolValue:
+                    row["valueBool"] = boolValue;
+                    break;
+                case sbyte or byte or short or ushort or int or uint or long or ulong or float or double or decimal:
+                    row["valueNum"] = Convert.ToDouble(value);
+                    break;
+                default:
+                    row["valueStr"] = value.ToString();
+                    break;
+            }
+
+            yield return row;
+        }
+    }
+
+    private async Task ExecuteQueryAsync(string query, IReadOnlyDictionary<string, object?> parameters)
+    {
+        var response = await _surrealClient.RawQueryAsync(query, parameters);
+        EnsureSuccessfulResponse(response, "Query execution");
+    }
+
+    private static string BuildContextId(int sequence)
+    {
+        return $"ctx-{sequence / 10:D6}";
+    }
+
+    private static string ResolveLogLevel(int sequence)
+    {
+        if (sequence % 2_500 == 0) return "Error";
+        if (sequence % 500 == 0) return "Warning";
+        return "Information";
+    }
+
+    private static long CalculatePathSizeBytes(string path)
+    {
+        if (File.Exists(path)) return new FileInfo(path).Length;
+        if (!Directory.Exists(path)) return 0;
+
+        long size = 0;
+        foreach (string file in Directory.EnumerateFiles(path, "*", SearchOption.AllDirectories))
+            size += new FileInfo(file).Length;
+
+        return size;
+    }
+
+    private static void EnsureSuccessfulResponse(SurrealDbResponse response, string operation)
+    {
+        if (!response.HasErrors) return;
+
+        string errorSummary = string.Join(
+            " | ",
+            response.Errors.Take(3).Select((error, index) => DescribeError(error, index)));
+
+        throw new InvalidOperationException(
+            $"{operation} failed with SurrealDB errors. Details: {errorSummary}");
+    }
+
+    private static string DescribeError(object error, int index)
+    {
+        Type errorType = error.GetType();
+        string[] fieldsToExtract = ["Status", "Details", "Description", "Information", "Code"];
+        var extracted = new List<string>();
+        foreach (string field in fieldsToExtract)
+        {
+            object? value = errorType.GetProperty(field)?.GetValue(error);
+            if (value != null) extracted.Add($"{field}={value}");
+        }
+
+        if (extracted.Count == 0) return $"error[{index}] type={errorType.Name}";
+        return $"error[{index}] type={errorType.Name} {string.Join(", ", extracted)}";
+    }
+}