A66: Automatic analyze of table completed

Example Postgres Log Output:

LOG: automatic analyze of table "postgres.public.pgbench_branches" system usage: CPU 1.02s/2.08u sec elapsed 108.25 sec

Explanation:

This log event, similar to A65 - Automatic vacuum of table completed, is controlled by log_autovacuum_min_duration, as both are started by the autovacuum launcher.

ANALYZE is the process of updating table statistics, and whilst it often runs together with VACUUM on a table, it can also run independently.

With ANALYZE its mostly CPU utilization that matters, which can also be seen by the smaller set of statistics compared to automatic VACUUM statistics.

Recommended Action:

Typically no action is needed based on this event. Sometimes it makes sense to adjust autovacuum_analyze_threshold or autovacuum_analyze_scale_factor to either reduce or increase the frequency of ANALYZE runs on specific tables.

That said, in most systems you will need to first spend time tuning the VACUUM settings of autovacuum, as that usually has higher impact on system performance and query plans.

Learn More:

• Postgres Documentation: Server Configuration - Automatic Vacuuming