PostgreSQLPerformance

Buffer cache hit ratio per database

Share of block reads served from shared buffers. OLTP databases usually sit above 99%; a drop suggests memory pressure or a new large scan.

Not yet verified. How scripts are tested

1SELECT datname,2       round(100.0 * blks_hit / NULLIF(blks_hit + blks_read, 0), 2) AS cache_hit_pct3FROM pg_stat_database4WHERE datname IS NOT NULL5ORDER BY cache_hit_pct;

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More PostgreSQL scripts: Performance

• Top statements by total timeNeeds the pg_stat_statements extension. Column names are for PostgreSQL 13 and later; on 12 and earlier use total_time and mean_time.