pg_stat_recovery_prefetch

PostgreSQL documentation ↗Source definition ↗

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.

First seen PG 15Last seen PG 19Columns 10

9.0 9.1 9.2 9.3 9.4 9.5 9.6 10 11 12 13 14 15 16 17 18 19^β3

Checked column by column against a PostgreSQL 18.6 instance · Raw measurement record ↗

Columns PostgreSQL 18

pg_stat_recovery_prefetch

COLUMN	TYPE	DESCRIPTION
`stats_reset`	`timestamp with time zone`	Time at which these statistics were last reset
`prefetch`	`bigint`	Number of blocks prefetched because they were not in the buffer pool
`hit`	`bigint`	Number of blocks not prefetched because they were already in the buffer pool
`skip_init`	`bigint`	Number of blocks not prefetched because they would be zero-initialized
`skip_new`	`bigint`	Number of blocks not prefetched because they didn't exist yet
`skip_fpw`	`bigint`	Number of blocks not prefetched because a full page image was included in the WAL
`skip_rep`	`bigint`	Number of blocks not prefetched because they were already recently prefetched
`wal_distance`	`integer`Documented as:`int`	How many bytes ahead the prefetcher is looking
`block_distance`	`integer`Documented as:`int`	How many blocks ahead the prefetcher is looking
`io_depth`	`integer`Documented as:`int`	How many prefetches have been initiated but are not yet known to have completed

Columns marked "implicit" are not included in SELECT *; some early statistics views are completed from same-version source, and the extra provenance is shown in the column description.

Column evolution matrix

Hover a cell for the column type

PresentAdded / type or attribute changeRemoved

COLUMN	9.0	9.1	9.2	9.3	9.4	9.5	9.6	10	11	12	13	14
`stats_reset`	–	–	–	–	–	–	–	–	–	–	–	–
`prefetch`	–	–	–	–	–	–	–	–	–	–	–	–
`hit`	–	–	–	–	–	–	–	–	–	–	–	–
`skip_init`	–	–	–	–	–	–	–	–	–	–	–	–
`skip_new`	–	–	–	–	–	–	–	–	–	–	–	–
`skip_fpw`	–	–	–	–	–	–	–	–	–	–	–	–
`skip_rep`	–	–	–	–	–	–	–	–	–	–	–	–
`wal_distance`	–	–	–	–	–	–	–	–	–	–	–	–
`block_distance`	–	–	–	–	–	–	–	–	–	–	–	–
`io_depth`	–	–	–	–	–	–	–	–	–	–	–	–

9.0 is the coverage baseline; a column already present in the baseline is not marked as added. The matrix aligns columns by name, so a rename appears as the old column removed and a new column added.

Evolution timeline

Changes between adjacent majors

PostgreSQL 15 ← 14Catalog added

+ stats_reset+ prefetch+ hit+ skip_init+ skip_new+ skip_fpw+ skip_rep+ wal_distance+ block_distance+ io_depth

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