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Wiki / Statistics & Metrics / pg_stat_io

pg_stat_io.write_time

Time spent waiting for write operations in milliseconds (if track_io_timing is enabled and object is not wal, or if track_wal_io_timing is enabled and object is wal, otherwise zero)

Reading PostgreSQL 18.6.

Description

Time spent waiting for write operations in milliseconds (if track_io_timing is enabled and object is not wal, or if track_wal_io_timing is enabled and object is wal, otherwise zero)

View
pg_stat_io
Field
write_time
SQL type
double precision
Units named in the field definition
milliseconds
Reset observation
Time at which these statistics were last reset.

Usage

SELECT write_time FROM pg_catalog.pg_stat_io;

View semantics

The pg_stat_io view will contain one row for each combination of backend type, target I/O object, and I/O context, showing cluster-wide I/O statistics. Combinations which do not make sense are omitted. Currently, I/O on relations (e.g. tables, indexes) and WAL activity are tracked. However, relation I/O which bypasses shared buffers (e.g. when moving a table from one tablespace to another) is currently not tracked.

Collection and reset context

Read the same-version statistics collection and view documentation below for reset scope and visibility. No per-field reset rule is inferred from the field name.

Inspect this field

Example query; no execution result or measured value is asserted.

SELECT write_time FROM pg_catalog.pg_stat_io;

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 15 → 16: added.

--- PostgreSQL 15
+++ PostgreSQL 16
@@ -1 +1,8 @@
-Not recorded in this version
+{
+  "field": "write_time",
+  "sql_type": "double precision",
+  "units_mentioned": [
+    "milliseconds"
+  ],
+  "view": "pg_stat_io"
+}

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

Export JSON · Back to Statistics & Metrics · Recorded in PostgreSQL 16 through 20; the first sample is not necessarily its introduction.