Causes each replication command and walsender process’s replication slot acquisition/release to be logged in the server log.
At a glance
| Property | Value |
|---|---|
| Parameter | log_replication_commands |
| Category | Error Reporting and Logging |
| Default | off |
| Value type | boolean (on/off) |
| Change scope | Per-session (SET) |
| Available in | PostgreSQL 12, 13, 14, 15, 16, 17, 18, 19 (added in 12) |
What it does
Causes each replication command and walsender process’s replication slot acquisition/release to be logged in the server log. See protocol_replication for more information about replication command. The default value is off. Only superusers and users with the appropriate SET privilege can change this setting.
(Description quoted from the official PostgreSQL documentation.)
How to apply a change
Can be set per session with SET, per role/database with ALTER ROLE/DATABASE ... SET, or globally in postgresql.conf.
Inspect the current value and source with SHOW log_replication_commands; or SELECT name, setting, unit, context, source FROM pg_settings WHERE name = 'log_replication_commands';.
Tuning guidance
Tune this for observability versus log volume, not for raw performance. More verbose logging helps diagnose problems but costs disk and I/O; quieter logging saves space but hides detail. Pick a level your log pipeline can store and search, and raise verbosity temporarily when investigating an incident.