perf(site-call-audit): filtered IX_SiteCalls_NonTerminal index — KPI predicates seek the live queue instead of scanning 365 days

docs/plans/sql/AddSiteCallsNonTerminalIndex.sql

@@ -0,0 +1,21 @@
+BEGIN TRANSACTION;
+IF NOT EXISTS (
+    SELECT * FROM [__EFMigrationsHistory]
+    WHERE [MigrationId] = N'20260709110614_AddSiteCallsNonTerminalIndex'
+)
+BEGIN
+    EXEC(N'CREATE INDEX [IX_SiteCalls_NonTerminal] ON [SiteCalls] ([CreatedAtUtc]) INCLUDE ([SourceSite], [SourceNode], [Status]) WHERE [TerminalAtUtc] IS NULL');
+END;
+
+IF NOT EXISTS (
+    SELECT * FROM [__EFMigrationsHistory]
+    WHERE [MigrationId] = N'20260709110614_AddSiteCallsNonTerminalIndex'
+)
+BEGIN
+    INSERT INTO [__EFMigrationsHistory] ([MigrationId], [ProductVersion])
+    VALUES (N'20260709110614_AddSiteCallsNonTerminalIndex', N'10.0.7');
+END;
+
+COMMIT;
+GO
+

src/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase/Configurations/SiteCallEntityTypeConfiguration.cs

@@ -66,8 +66,9 @@ public class SiteCallEntityTypeConfiguration : IEntityTypeConfiguration<SiteCall
         // SourceNode (SourceNode-stamping): node-local identifier of the
         // cluster member that produced the call (e.g. "node-a", "central-a"). NULL is
         // valid for rows that pre-date this feature and for reconciled rows from a
-        // retired node. ASCII — varchar(64). No index — Site Call Audit KPIs are
-        // per-site, not per-node, on this table.
+        // retired node. ASCII — varchar(64). Not a key column of any index, but it rides
+        // as an INCLUDE column on IX_SiteCalls_NonTerminal below so the per-node KPI
+        // breakdown reads it covered off the filtered live-queue index.
         builder.Property(s => s.SourceNode)
             .HasColumnType("varchar(64)")
             .HasMaxLength(64)
@@ -85,5 +86,16 @@ public class SiteCallEntityTypeConfiguration : IEntityTypeConfiguration<SiteCall
         builder.HasIndex(s => new { s.Status, s.UpdatedAtUtc })
             .IsDescending(false, true)
             .HasDatabaseName("IX_SiteCalls_Status_Updated");
+
+        // NonTerminal backs every "live queue" KPI predicate (TerminalAtUtc IS NULL):
+        // buffered/stuck/oldest counts run every 60 s from the KPI recorder plus every
+        // 10 s Health-dashboard poll. Filtered: the non-terminal population is the live
+        // queue, not the 365-day archive — each count becomes a small seek instead of a
+        // clustered scan (arch-review 04, P1). SourceSite/SourceNode/Status ride as
+        // INCLUDE columns so the per-site + per-node KPI breakdowns stay covered.
+        builder.HasIndex(s => s.CreatedAtUtc)
+            .HasDatabaseName("IX_SiteCalls_NonTerminal")
+            .HasFilter("[TerminalAtUtc] IS NULL")
+            .IncludeProperties(nameof(SiteCall.SourceSite), nameof(SiteCall.SourceNode), nameof(SiteCall.Status));
     }
 }

src/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase/Migrations/20260709110614_AddSiteCallsNonTerminalIndex.cs

@@ -0,0 +1,29 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddSiteCallsNonTerminalIndex : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateIndex(
+                name: "IX_SiteCalls_NonTerminal",
+                table: "SiteCalls",
+                column: "CreatedAtUtc",
+                filter: "[TerminalAtUtc] IS NULL")
+                .Annotation("SqlServer:Include", new[] { "SourceSite", "SourceNode", "Status" });
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropIndex(
+                name: "IX_SiteCalls_NonTerminal",
+                table: "SiteCalls");
+        }
+    }
+}

src/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase/Migrations/ScadaBridgeDbContextModelSnapshot.cs

@@ -161,6 +161,12 @@ namespace ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Migrations
 
                     b.HasKey("TrackedOperationId");
 
+                    b.HasIndex("CreatedAtUtc")
+                        .HasDatabaseName("IX_SiteCalls_NonTerminal")
+                        .HasFilter("[TerminalAtUtc] IS NULL");
+
+                    SqlServerIndexBuilderExtensions.IncludeProperties(b.HasIndex("CreatedAtUtc"), new[] { "SourceSite", "SourceNode", "Status" });
+
                     b.HasIndex("SourceSite", "CreatedAtUtc")
                         .IsDescending(false, true)
                         .HasDatabaseName("IX_SiteCalls_Source_Created");

tests/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Tests/SchemaConfigurationTests.cs

@@ -1,4 +1,7 @@
 using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Metadata;
+using ZB.MOM.WW.ScadaBridge.Commons.Entities.Audit;
 using ZB.MOM.WW.ScadaBridge.Commons.Entities.ExternalSystems;
 using ZB.MOM.WW.ScadaBridge.Commons.Entities.Notifications;
 using ZB.MOM.WW.ScadaBridge.Commons.Entities.Sites;
@@ -70,6 +73,27 @@ public class SchemaConfigurationTests : IDisposable
 
         Assert.IsType<EncryptedStringConverter>(converter);
     }
+
+    // arch-review 04 (P1): the SiteCalls "live queue" KPI predicates all filter on
+    // TerminalAtUtc IS NULL and run every 60 s (KPI recorder) + every 10 s (Health poll).
+    // A filtered index over just the non-terminal rows turns each count from a clustered
+    // scan of the 365-day archive into a small seek. Locked shape:
+    // key = CreatedAtUtc, filter = [TerminalAtUtc] IS NULL, INCLUDE SourceSite/SourceNode/Status.
+    [Fact]
+    public void SiteCalls_Has_Filtered_NonTerminal_Index()
+    {
+        // IncludeProperties is a SQL-Server-only annotation stripped from the runtime
+        // read-optimized model, so read the design-time model where it is preserved.
+        var model = _context.GetService<IDesignTimeModel>().Model;
+        var entity = model.FindEntityType(typeof(SiteCall))!;
+        var index = entity.GetIndexes().Single(i => i.GetDatabaseName() == "IX_SiteCalls_NonTerminal");
+
+        Assert.Equal(new[] { nameof(SiteCall.CreatedAtUtc) }, index.Properties.Select(p => p.Name));
+        Assert.Equal("[TerminalAtUtc] IS NULL", index.GetFilter());
+        Assert.Equal(
+            new[] { nameof(SiteCall.SourceSite), nameof(SiteCall.SourceNode), nameof(SiteCall.Status) },
+            index.GetIncludeProperties());
+    }
 }
 
 public class SplitQueryBehaviourTests : IDisposable