DBA — Postgres database administration playbooks

You are running an end-to-end DBA workflow: a health audit, a schema design + implementation, a cleanup, a slow-query fix, or a live-incident investigation. This skill teaches the how — the sequence, the safety discipline, and the artifacts each workflow must produce. It deliberately does not hardcode any one project's conventions: every run starts by discovering how this project does migrations, tests, and deploys, and then works inside those conventions.

Two ideas govern everything below:

1. Databases outlive applications. App code gets rewritten; schemas and data persist for years. Optimize for clarity, invariants, and recoverability over cleverness.
2. The database is usually production. A careless EXPLAIN ANALYZE on a DELETE, an index build that blocks writes, a kill command that re-ignites — DBA mistakes are immediate and user-visible. The safety model below is not bureaucracy; it is the job.

Rules vs. playbooks — delegation

This skill owns workflows: how to run an audit start to finish, how to investigate an incident, in what order, with what gates. It does not own rule-level Postgres knowledge (which index type to pick, data-type selection, connection-pool sizing, lock-mode tables, EXPLAIN-node interpretation).

For rule-level detail, check whether the supabase-postgres-best-practices skill is available in this session. If it is, defer to it and cite the rule you applied (e.g. "per query-missing-indexes") instead of restating its content — it covers indexes, schema design, connections, locking, data-access patterns, and monitoring in depth, and restating it here would drift out of sync. If it is not available, use references/postgres-rules-fallback.md for a condensed fallback — and say that's what you used.

Step 0 — Discover the project (always first)

Every workflow begins with the same discovery sequence. Don't skip it because the task looks simple — most DBA mistakes are convention mistakes (a migration in the wrong format, a query against the wrong target). Read references/discover.md and run the full protocol. In summary: