Module postgres 

Postgres backend for the audit log.

Wire-compatible with AWS RDS / Aurora, GCP Cloud SQL + AlloyDB, Azure Database for PostgreSQL Flexible Server, Supabase (direct + pooler), Neon (direct + pooler), and self-hosted Postgres.

Connection lifecycle

PostgresStore::connect takes a PostgresConfig (URL plus pool + statement-cache tuning) and returns a configured sqlx::PgPool. The same pool is used for every request — sqlx handles connection reuse, retry on broken connections, and TLS via rustls.

On connect, PostgresStore::initialize runs ordered, transactional schema migrations under a database advisory lock. Existing installations created before migration tracking are adopted by migration 1 without dropping or rewriting rows. The schema mirrors SQLite field-for-field; the only dialect difference is BIGINT NOT NULL UNIQUE for seq. created_at remains TEXT (RFC 3339 with Z suffix) in both backends and is cast to timestamptz for interval arithmetic.

Concurrency

Like the SQLite path, the chain-hash + seq computation is wrapped in a BEGIN ... COMMIT block. Postgres serialises this naturally via row-level locks on the seq write; we use a SELECT … FOR UPDATE on the most-recent row so concurrent writers see the same predecessor and the second commit fails atomically rather than corrupting the chain.

Structs

PostgresConfig

Configuration for the Postgres backend. Built by main.rs from [storage] in config.toml.

PostgresStore

Postgres-backed AuditStore.