migrate / audit · 01 — Four tables

History as data, not log lines.

Migration audit lives in four real Postgres tables, each with a clear shape and a clear question. Wire monitoring against them, replay history, build post-mortems. No log scraper required.

_zanith_migrationsapplied

Answers which migrations have run, when.

1 row per applied migration

_zanith_migration_stepsper-step audit

Answers every op's status, risk, error, SQL.

N rows per migration

_zanith_schema_snapshotsbefore/after

Answers the runtime graph at each side of the apply.

2 rows per migration

_zanith_migration_artifactsrecovery

Answers which destructive ops are still reversible.

1 row per Phase-2 op

4 tables · 0 sidecar servicessame DB as your appidempotent re-creationv0.2 · shipped

02 — Four shapes

Each table has its own shape.

Narrow tables for the high-volume rows, wide tables for the ones that capture detail. All four created idempotently when the runner first connects.

_zanith_migrationsapplied set

Which migrations have run, in what order.

shape

30-day fill14 rows

cardinality

1 row per migration

storage

negligible

_zanith_migration_stepsper-step audit

Every op's status, risk, error, and SQL.

shape

30-day fill86 rows

cardinality

N rows per migration

storage

small (~200B per row)

_zanith_schema_snapshotsbefore / after

The schema graph at each side of the apply.

shape

30-day fill28 rows

cardinality

2 rows per migration

storage

moderate (10–50KB each)

_zanith_migration_artifactsrecovery

Which destructive ops are still reversible.

shape

30-day fill5 rows

cardinality

1 row per Phase-2 op

storage

small (archive data is separate)

03 — History + replay

Reconstruct any past state.

History is a join across the four tables. Every applied migration leaves a row, a per-step audit, and two snapshots (before + after). Reconstruct the schema from any point in time without restoring a backup.

applied · most recent first3 migrations

add_last_logindestructive · 804 stepsMay 01, 11:30
20260501_113022_add_last_login
add_user_indexeslow · 152 stepsApr 28, 14:18
20260428_141755_add_user_indexes
initialsafe · 57 stepsApr 20, 09:20
20260420_092011_initial

snapshot · before

14 models · 86 fields

captured 2026-05-01T11:30:21Z

snapshot · after

14 models · 87 fields

captured 2026-05-01T11:30:23Z

Snapshots are stored as JSON in _zanith_schema_snapshots. Diff any two to see exactly what changed between releases.

04 — Questions answered

Six questions your audit table answers.

Each one is a one-page Grafana panel, a Slack alert, or a monthly engineering review row away. The data lives in the same Postgres your app uses — no log scraper, no sidecar.