AuditMaintenanceGrants (migration 64) landed after the flip and adds
GRANT UPDATE (SourceNode) to the purger, but the tests still migrated "back
up" only to the flip and asserted the pre-64 grant list, so the class failed
in either test order (the grant missing after DownUp, or unexpected before).
Restore to head and compare the down state against the pre-64 grant set.
Co-Authored-By: Claude <noreply@anthropic.com>
Variant B2 of the #78 benchmark: migration FlipAuditLogClusteredKey drops the
twelve non-clustered indexes, re-adds PK_AuditLog as (OccurredAtUtc, EventId)
on ps_AuditLog_Month, adds the aligned unique UX_AuditLog_EventId_Occurred
(EventId, OccurredAtUtc) for the idempotency probe, and rebuilds the twelve
indexes unchanged. Guarded (re-runnable) Up, inverse-rebuild Down; production
scripts docs/plans/sql/FlipAuditLogClusteredKey{,.rollback}.sql.
The partition-switch purge staging table now reads the live clustered key
order from sys.index_columns, so it switches either shape (old binaries
hard-code the old order: ship with the binaries, both centrals stopped).
Evidence: 300k rows, page 1 90,532 -> 34 logical reads (ordered backward
clustered scan under Top), keyset page 90,532 -> 46, probe 14 -> 14;
FlipAuditLogClusteredKeyMigrationTests pins indexes, grants, Down/Up, the
staging key (mutation: hard-coded old key fails SWITCH) and the read ratio.
Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV
Joseph Doherty