Bundle C of the #23 M1 foundation. Creates the centralized AuditLog table
with the partition function, partition scheme, partition-aligned
non-clustered indexes, and the two access-control roles documented in
alog.md §4.
Schema:
- pf_AuditLog_Month: RANGE RIGHT, 24 monthly boundaries (Jan 2026 – Dec 2027).
- ps_AuditLog_Month: ALL TO ([PRIMARY]) — dev/test parity.
- dbo.AuditLog: created via raw SQL ON ps_AuditLog_Month(OccurredAtUtc).
Composite clustered PK {EventId, OccurredAtUtc} (partition column must be
part of the clustered key). 22 columns matching the EF AuditEvent model.
- 5 reconciliation/query non-clustered indexes from alog.md §4
(Channel_Status_Occurred, CorrelationId filtered, OccurredAtUtc,
Site_Occurred, Target_Occurred filtered) — all partition-aligned.
- UX_AuditLog_EventId: non-aligned UNIQUE on EventId alone (preserves
InsertIfNotExistsAsync idempotency from M1-T8). Non-aligned because
partition-aligned unique indexes require the partition column in the key,
which would weaken to composite uniqueness; the purge story (M2/M3)
rebuilds this index around partition switches.
Access control:
- scadalink_audit_writer: GRANT INSERT + GRANT SELECT, DENY UPDATE + DENY DELETE
on AuditLog. The explicit DENY guarantees later db_datawriter membership
cannot quietly re-enable mutation.
- scadalink_audit_purger: GRANT SELECT on AuditLog, GRANT ALTER on SCHEMA::dbo
(enables ALTER PARTITION FUNCTION SWITCH and SWITCH PARTITION).
Both role definitions are idempotent (IF DATABASE_PRINCIPAL_ID IS NULL).
Down() drops in reverse dependency order with IF EXISTS guards.
Integration tests (tests/ScadaLink.ConfigurationDatabase.Tests/Migrations/):
- MsSqlMigrationFixture: connects to the running infra/mssql container (or
the SCADALINK_MSSQL_TEST_CONN override), creates a unique per-fixture
database, applies the migrations, drops the DB on dispose. Marks itself
Available=false when MSSQL is unreachable so tests early-return cleanly
on CI without the dev container.
- AddAuditLogTableMigrationTests: 8 tests covering table existence,
partition function/scheme, partition-aligned PK, the 5 named indexes,
both roles' grants, and a smoke test that a writer-role user receives
SqlException with "permission" on UPDATE AuditLog.
ConfigurationDatabase tests: 142 passing -> 150 passing (8 new integration
tests). Full solution builds clean.
Package: tests project locally overrides Microsoft.Data.SqlClient to 6.1.1
(EF SqlServer 10.0.7 needs >= 6.1.1; central package version is pinned at
6.0.2 for the production ExternalSystemGateway).
