pg_ash v1 - Active Session History for PostgreSQL

Posted on 2026-04-03 by PostgresAI
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pg_ash samples pg_stat_activity once per second via pg_cron, stores encoded snapshots in partitioned tables, and provides 32 SQL functions for wait event analysis.

Pure SQL + PL/pgSQL. No C extension, no shared_preload_libraries, no restart required. Works anywhere pg_cron runs — managed providers (RDS, Cloud SQL, AlloyDB, Azure Database for PostgreSQL, Supabase, etc.), self-managed, Kubernetes, or any other deployment.

Storage: ~100-200 bytes per sample, ~30 MiB/day with TRUNCATE-based partition rotation (zero bloat).

Analysis functions include top waits, per-query wait profiles, wait event drill-down, time-range investigation, and timeline visualization. Functions are designed to chain naturally for iterative root cause analysis — by a human in psql or by AI tools such as Claude Code, OpenCode, or Codex.

PostgreSQL 14-18. Apache 2.0. CI tested.

https://github.com/NikolayS/pg_ash