Skip to content

PostgreSQL Logging Tuning Guide

Parameters

1. log_min_messages

The PostgreSQL process can log extra information.
Default is to log warning and worse (error, fatal, panic), which is the recommended value.
This value is for generic purposes. For statement processing, see log_min_error_statement.

2. log_min_error_statement

The PostgreSQL process can, while processing a statement, log extra information.
Default is to log error and worse (fatal, panic), which is the recommended value.

3. log_min_duration_statement

PostgreSQL can log statements that take longer than a certain amount of time.

  • Default is disabled (-1).
  • A value of 0 always logs all statements.
  • Recommended value:
  • Set as per business requirement (defined by the database requestor).
  • Use 10 seconds when no business requirement exists.

4. log_autovacuum_min_duration

PostgreSQL can log vacuums initiated by autovacuum that take longer than a certain amount of time.
Recommendation: Set this value to 10 seconds, so that longer vacuums stand out.

5. log_checkpoints

PostgreSQL can track checkpoints.
Recommendation:
- Set to on and monitor checkpoint frequency.
- Once or twice per minute (or less) is acceptable.
- More frequent checkpoints (dozens per minute) may indicate excessive WAL usage or that max_wal_size is too small and needs immediate attention.

6. log_connections, log_disconnections

PostgreSQL can track connections and disconnections.
However, when PEM agents are used (logging every second), enabling these settings floods the logs.

Recommendation: Keep these settings off unless:
- There are audit requirements.
- You are debugging connection issues.

7. log_duration

PostgreSQL can log the duration of long-running statements.
Recommendation: Enable this feature (very small overhead).

8. log_error_verbosity

PostgreSQL can log more or less detail.

  • Default value: default (recommended).
  • Setting this parameter to verbose can be helpful when investigating an issue — only temporarily.
  • Setting to terse is not required.

9. log_statement

PostgreSQL can be configured to monitor specific statements.
Default is none.
Recommendation: Set to ddl to ensure schema changes are logged.

10. log_temp_files

PostgreSQL can log temp files that are larger than a certain size.
Recommendation: Log temp files when they are larger than work_mem, as this indicates that increasing work_mem could be beneficial.