postgresql/doc
Alexander Korotkov dc9f8a7983 Track statement entry timestamp in contrib/pg_stat_statements
This patch adds 'stats_since' and 'minmax_stats_since' columns to the
pg_stat_statements view and pg_stat_statements() function.  The new min/max
reset mode for the pg_stat_stetments_reset() function is controlled by the
parameter minmax_only.

'stat_since' column is populated with the current timestamp when a new
statement is added to the pg_stat_statements hashtable.  It provides clean
information about statistics collection time intervals for each statement.
Besides it can be used by sampling solutions to detect situations when a
statement was evicted and stored again between samples.

Such a sampling solution could derive any pg_stat_statements statistic values
for an interval between two samples with the exception of all min/max
statistics. To address this issue this patch adds the ability to reset
min/max statistics independently of the statement reset using the new
minmax_only parameter of the pg_stat_statements_reset(userid oid, dbid oid,
queryid bigint, minmax_only boolean) function. The timestamp of such reset
is stored in the minmax_stats_since field for each statement.
pg_stat_statements_reset() function now returns the timestamp of a reset as the
result.

Discussion: https://postgr.es/m/flat/72e80e7b160a6eb189df9ef6f068cce3765d37f8.camel%40moonset.ru
Author: Andrei Zubkov
Reviewed-by: Julien Rouhaud, Hayato Kuroda, Yuki Seino, Chengxi Sun
Reviewed-by: Anton Melnikov, Darren Rush, Michael Paquier, Sergei Kornilov
Reviewed-by: Alena Rybakina, Andrei Lepikhov
2023-11-27 02:52:17 +02:00
..
src Track statement entry timestamp in contrib/pg_stat_statements 2023-11-27 02:52:17 +02:00
KNOWN_BUGS
MISSING_FEATURES
Makefile Remove distprep 2023-11-06 15:18:04 +01:00
TODO Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00