pg_stat_bgwriter — PostgreSQL statistics view

Summary

The pg_stat_bgwriter view will always have a single row, containing data about the background writer of the cluster.

(Description quoted from the official PostgreSQL documentation.)

Columns

The pg_stat_bgwriter statistics view exposes the following columns (names, types and descriptions are taken verbatim from the PostgreSQL documentation):

• buffers_clean bigint
  Number of buffers written by the background writer
• maxwritten_clean bigint
  Number of times the background writer stopped a cleaning scan because it had written too many buffers
• buffers_alloc bigint
  Number of buffers allocated
• stats_reset timestamp with time zone
  Time at which these statistics were last reset

Version applicability

Present in PostgreSQL 17, 18, 19 (verified against each release’s documentation). This is a long-standing system object that also exists in earlier PostgreSQL releases.

Related & references

• PostgreSQL system catalog & view index
• Built-in function reference

Reference: PostgreSQL documentation — pg_stat_bgwriter.