What's New with Monitoring in PostgreSQL 19

Summary

PostgreSQL 19, still in beta when this was written, adds monitoring and observability changes spanning lock contention, logging, WAL, wait events, remote messages, and multixacts. The default for log_lock_waits changes to on, while log_min_messages gains per-process-type levels and autoanalyze receives its own duration setting. A new wal_fpi_bytes counter exposes full-page-image volume cluster-wide, per session, per query, and in VACUUM and ANALYZE logs; new wait events expose WAL write, flush, and replay stages plus COPY file, pipe, and program I/O. Remote server messages now use normal PostgreSQL logging with origin prefixes, and pg_get_multixact_stats() surfaces multixact usage that previously required filesystem inspection and educated guessing. The post also lists upgrade work for parsers, metric collectors, wait-event dictionaries, configuration UIs, and alert thresholds, while noting that final release notes may differ.

Takeaways

1. 1

   log_min_messages can use process type:level pairs, allowing different verbosity for processes such as checkpointer and autovacuum while retaining a mandatory fallback level.

2. 2

   wal_fpi_bytes is available in pg_stat_wal, per-session statistics, EXPLAIN (ANALYZE, WAL), and VACUUM or ANALYZE logs, enabling comparison with wal_bytes.

3. 3

   After upgrading, log parsers and metric collectors need updates for separate autoanalyze logging, new WAL log fields, new wait events, and pg_get_multixact_stats().