diff options
| author | Fujii Masao <fujii@postgresql.org> | 2020-05-22 23:33:58 +0900 |
|---|---|---|
| committer | Fujii Masao <fujii@postgresql.org> | 2020-05-22 23:33:58 +0900 |
| commit | eaae947e2b99a84c8f321fe084d87daff0f77d02 (patch) | |
| tree | 5a921e0c4c25f04ed9d89d3c2d7a51d11ee80f74 /doc/src/sgml/monitoring.sgml | |
| parent | 574925bfd0a8175f6e161936ea11d9695677ba09 (diff) | |
doc: Add note about I/O timing information in EXPLAIN and pg_stat_database.
Explain that the followings are tracked only when track_io_timing GUC
is enabled.
- blk_read_time and blk_write_time in pg_stat_database
- time spent reading and writing data file blocks in EXPLAIN output
with BUFFERS option
Whther track_io_timing is enabled affects also blk_read_time and
blk_write_time in pg_stat_statements, but which was already documented.
Author: Atsushi Torikoshi
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/CACZ0uYHo_NwbxpLH76OGF-O=13tkR0ZM0zeyGEhZ+JEXZVRyCA@mail.gmail.com
Diffstat (limited to 'doc/src/sgml/monitoring.sgml')
| -rw-r--r-- | doc/src/sgml/monitoring.sgml | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index acc6e2bc316..49d4bb13b9e 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -3390,7 +3390,8 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i </para> <para> Time spent reading data file blocks by backends in this database, - in milliseconds + in milliseconds (if <xref linkend="guc-track-io-timing"/> is enabled, + otherwise zero) </para></entry> </row> @@ -3400,7 +3401,8 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i </para> <para> Time spent writing data file blocks by backends in this database, - in milliseconds + in milliseconds (if <xref linkend="guc-track-io-timing"/> is enabled, + otherwise zero) </para></entry> </row> |