Wiki / Configuration Parameters

Determines the behavior when cumulative statistics are accessed multiple times within a transaction. When set to none, each access re-fetches counters from shared memory. When set to cache, the first access to statistics for an object caches those statistics until the end of the transaction unless pg_stat_clear_snapshot() is called. When set to snapshot, the first statistics access caches all statistics accessible in the current database, until the end of the transaction unless pg_stat_clear_snapshot() is called. Changing this parameter in a transaction discards the statistics snapshot. The default is cache. Note none is most suitable for monitoring systems. If values are only accessed once, it is the most efficient. cache ensures repeat accesses yield the same values, which is important for queries involving e.g. self-joins. snapshot can be useful when interactively inspecting statistics, but has higher overhead, particularly if many database objects exist.

English manual coverage begins with PostgreSQL 7.4. Source history and runtime observations have their own recorded version boundaries.

boot val

cache

category

Statistics / Cumulative Query and Index Statistics

context

user

documented

true

enumvals

none, cache, snapshot

extra desc

Unknown

lang

en

max val

Unknown

metadata version

18

min val

Unknown

name

stats_fetch_consistency

short desc

Sets the consistency of accesses to statistics data.

source

pg-settings-source-snapshot

unit

Unknown

vartype

enum