pg_stat_slru — PostgreSQL statistics view

Summary

PostgreSQL accesses certain on-disk information via SLRU (simple least-recently-used) caches. The pg_stat_slru view will contain one row for each tracked SLRU cache, showing statistics about access to cached pages.

(Description quoted from the official PostgreSQL documentation.)

Columns

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

• name text
  Name of the SLRU
• blks_zeroed bigint
  Number of blocks zeroed during initializations
• blks_hit bigint
  Number of times disk blocks were found already in the SLRU, so that a read was not necessary (this only includes hits in the SLRU, not the operating system’s file system cache)
• blks_read bigint
  Number of disk blocks read for this SLRU
• blks_written bigint
  Number of disk blocks written for this SLRU
• blks_exists bigint
  Number of blocks checked for existence for this SLRU
• flushes bigint
  Number of flushes of dirty data for this SLRU
• truncates bigint
  Number of truncates for this SLRU
• 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_slru.