pg_stat_recovery_prefetch.wal_distance

Description

How many bytes ahead the prefetcher is looking

View

pg_stat_recovery_prefetch

Field

wal_distance

SQL type

int

Units named in the field definition

bytes

Reset observation

Time at which these statistics were last reset

Usage

SELECT wal_distance 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 wal_distance FROM pg_catalog.pg_stat_recovery_prefetch;

Related entries

• pg_stat_recovery_prefetch columns
• Statistics collection and reset functions

Documentation and source

• PostgreSQL 18 English manual

Compare versions

PostgreSQL 14 → 15: added.

--- PostgreSQL 14
+++ PostgreSQL 15
@@ -1 +1,8 @@
-Not recorded in this version
+{
+  "field": "wal_distance",
+  "sql_type": "int",
+  "units_mentioned": [
+    "bytes"
+  ],
+  "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_distance
• pg_stat_recovery_prefetch.hit
• pg_stat_recovery_prefetch.io_depth
• pg_stat_recovery_prefetch.prefetch
• pg_stat_recovery_prefetch.skip_fpw
• pg_stat_recovery_prefetch.skip_init
• pg_stat_recovery_prefetch.skip_new
• pg_stat_recovery_prefetch.skip_rep
• pg_stat_recovery_prefetch.stats_reset