diff --git a/src/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase/Configurations/AuditLogEntityTypeConfiguration.cs b/src/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase/Configurations/AuditLogEntityTypeConfiguration.cs
index 217686ad..221418f2 100644
--- a/src/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase/Configurations/AuditLogEntityTypeConfiguration.cs
+++ b/src/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase/Configurations/AuditLogEntityTypeConfiguration.cs
@@ -8,8 +8,11 @@ namespace ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Configurations;
 /// <summary>
 /// Maps the C5 (Task 2.5) <see cref="AuditLogRow"/> persistence shape to the central
 /// <c>dbo.AuditLog</c> table: the 10 canonical <c>ZB.MOM.WW.Audit.AuditEvent</c> columns
-/// (writable) plus six read-only, server-side <b>persisted computed columns</b> derived
-/// from <c>DetailsJson</c> via <c>JSON_VALUE</c>. The computed-column SQL and the index
+/// (writable) plus six read-only, server-side <b>computed columns</b> derived from
+/// <c>DetailsJson</c> via <c>JSON_VALUE</c> — five PERSISTED (<c>Kind</c>/<c>Status</c>/
+/// <c>SourceSiteId</c>/<c>ExecutionId</c>/<c>ParentExecutionId</c>) plus <c>IngestedAtUtc</c>
+/// which is computed but NOT persisted (SQL Server forbids PERSISTED on its non-deterministic
+/// <c>SWITCHOFFSET</c> cast). The computed-column SQL and the index
 /// set here mirror the <c>CollapseAuditLogToCanonical</c> migration's
 /// <c>dbo.AuditLog_v2</c> DDL byte-for-byte — keep them in sync.
 /// </summary>
diff --git a/src/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase/Migrations/20260602174346_CollapseAuditLogToCanonical.cs b/src/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase/Migrations/20260602174346_CollapseAuditLogToCanonical.cs
index d1ecac0e..2478e243 100644
--- a/src/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase/Migrations/20260602174346_CollapseAuditLogToCanonical.cs
+++ b/src/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase/Migrations/20260602174346_CollapseAuditLogToCanonical.cs
@@ -46,8 +46,8 @@ namespace ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Migrations
         protected override void Up(MigrationBuilder migrationBuilder)
         {
             // 1) Create dbo.AuditLog_v2 on the PRESERVED partition scheme. Ten
-            //    canonical columns first (ordinal-stable), then the six persisted
-            //    computed columns. The clustered PK is composite {EventId,
+            //    canonical columns first (ordinal-stable), then the six computed
+            //    columns (five PERSISTED + IngestedAtUtc non-persisted). The clustered PK is composite {EventId,
             //    OccurredAtUtc} (partition-aligned). The computed-column expressions
             //    here are the single source of truth that AuditLogEntityTypeConfiguration
             //    and SwitchOutPartitionAsync's staging table must mirror exactly.
diff --git a/tests/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Tests/Migrations/CollapseAuditLogToCanonicalMigrationTests.cs b/tests/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Tests/Migrations/CollapseAuditLogToCanonicalMigrationTests.cs
index 36d07b5a..03302319 100644
--- a/tests/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Tests/Migrations/CollapseAuditLogToCanonicalMigrationTests.cs
+++ b/tests/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Tests/Migrations/CollapseAuditLogToCanonicalMigrationTests.cs
@@ -6,7 +6,7 @@ namespace ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Tests.Migrations;
 
 /// <summary>
 /// C7 (Task 2.5) data-projection tests for the <c>CollapseAuditLogToCanonical</c>
-/// migration. Verifies that the canonical column layout and six persisted computed
+/// migration. Verifies that the canonical column layout and the five persisted computed
 /// columns are correct after the migration has been applied:
 /// <list type="bullet">
 ///   <item><c>Action</c> = "{Channel}.{Kind}" per <see cref="AuditFieldBuilders.BuildAction"/>.</item>
@@ -17,9 +17,10 @@ namespace ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Tests.Migrations;
 ///     else → <c>Success</c>.</item>
 ///   <item>Empty <c>Actor</c> maps to NULL.</item>
 ///   <item><c>DetailsJson</c> produced by <see cref="AuditDetailsCodec.Serialize"/> round-trips
-///     correctly and the six persisted computed columns (<c>Kind</c>, <c>Status</c>,
+///     correctly and the five persisted computed columns (<c>Kind</c>, <c>Status</c>,
 ///     <c>SourceSiteId</c>, <c>ExecutionId</c>, <c>ParentExecutionId</c>) resolve to
-///     the expected values via <c>JSON_VALUE</c>.</item>
+///     the expected values via <c>JSON_VALUE</c> (<c>IngestedAtUtc</c> is computed but
+///     non-persisted, so not asserted here).</item>
 /// </list>
 /// </summary>
 /// <remarks>
@@ -30,7 +31,7 @@ namespace ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Tests.Migrations;
 /// seed, apply C5), the tests insert rows directly into the canonical table using
 /// <see cref="AuditDetailsCodec"/> — the same codec the migration's
 /// <c>FOR JSON PATH, WITHOUT_ARRAY_WRAPPER</c> projection is designed to match —
-/// and verify that all six computed columns resolve correctly from <c>DetailsJson</c>.
+/// and verify that the five persisted computed columns resolve correctly from <c>DetailsJson</c>.
 /// This validates the computed-column SQL expressions that are the source of truth
 /// for both the live table and <c>SwitchOutPartitionAsync</c>'s staging table.
 /// </para>
diff --git a/tests/ZB.MOM.WW.ScadaBridge.PerformanceTests/AuditLog/HotPathLatencyTests.cs b/tests/ZB.MOM.WW.ScadaBridge.PerformanceTests/AuditLog/HotPathLatencyTests.cs
index 70458f43..f033e9fa 100644
--- a/tests/ZB.MOM.WW.ScadaBridge.PerformanceTests/AuditLog/HotPathLatencyTests.cs
+++ b/tests/ZB.MOM.WW.ScadaBridge.PerformanceTests/AuditLog/HotPathLatencyTests.cs
@@ -29,8 +29,8 @@ namespace ZB.MOM.WW.ScadaBridge.PerformanceTests.AuditLog;
 /// <b>C7 re-baseline rationale.</b> The canonical <see cref="ScadaBridgeAuditRedactor"/>
 /// works on a single <c>DetailsJson</c> bag (one JSON parse + one re-serialize per
 /// call) whereas the former typed-field approach touched many individual
-/// fields. Empirical measurements on Apple M-series (2026-06-02, Release build,
-/// 5 000 iterations after 500 warm-ups):
+/// fields. Empirical calibration measurements on Apple M-series (2026-06-02, Release build;
+/// the CI test itself runs MeasureIterations=2 000 after WarmupIterations=200):
 /// <list type="bullet">
 ///   <item>4 KB body (2 body-regex matches + truncation): p50 ≈ 13 µs, p95 ≈ 14 µs.</item>
 ///   <item>Small DetailsJson, no redactors (JSON parse + rewrite only): p50 ≈ 1.5 µs, p95 ≈ 2 µs.</item>