Wiki / Statistics & Metrics / pg_stat_recovery_prefetch
pg_stat_recovery_prefetch.hit
Number of blocks not prefetched because they were already in the buffer pool
Reading PostgreSQL 18.6.
Description
Number of blocks not prefetched because they were already in the buffer pool
- View
- pg_stat_recovery_prefetch
- Field
- hit
- SQL type
- bigint
- Units named in the field definition
- blocks
- Reset observation
- Time at which these statistics were last reset
Usage
SELECT hit FROM pg_catalog.pg_stat_recovery_prefetch;View semantics
The pg_stat_recovery_prefetch view will contain only one row. The columns wal_distance, block_distance and io_depth show current values, and the other columns show cumulative counters that can be reset with the pg_stat_reset_shared function.
Collection and reset context
The pg_stat_recovery_prefetch view will contain only one row. The columns wal_distance , block_distance and io_depth show current values, and the other columns show cumulative counters that can be reset with the pg_stat_reset_shared function.
Inspect this field
Example query; no execution result or measured value is asserted.
SELECT hit FROM pg_catalog.pg_stat_recovery_prefetch;Related entries
Documentation and source
Source build
- Version
- 18.6
- Build
- https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2
- Source fingerprint
555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f
Compare versions
PostgreSQL 14 → 15: added.
--- PostgreSQL 14
+++ PostgreSQL 15
@@ -1 +1,8 @@
-Not recorded in this version
+{
+ "field": "hit",
+ "sql_type": "bigint",
+ "units_mentioned": [
+ "blocks"
+ ],
+ "view": "pg_stat_recovery_prefetch"
+}
Compares recorded interfaces and attributes. Source fingerprints and build metadata are excluded; an absent sample is not proof of the introduction or removal release.
Related entries
pg_stat_recovery_prefetch.block_distancepg_stat_recovery_prefetch.io_depthpg_stat_recovery_prefetch.prefetchpg_stat_recovery_prefetch.skip_fpwpg_stat_recovery_prefetch.skip_initpg_stat_recovery_prefetch.skip_newpg_stat_recovery_prefetch.skip_reppg_stat_recovery_prefetch.stats_resetpg_stat_recovery_prefetch.wal_distance
Export JSON · Back to Statistics & Metrics · Recorded in PostgreSQL 15 through 20; the first sample is not necessarily its introduction.