Horton

Track shared buffer hits in pg_stat_io

Andres Freund <andres@anarazel.de>

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Commit: 8aaa04b32d790da595684de58ae4fc2db96becff
Author: Andres Freund <andres@anarazel.de>
Date: 2023-03-31T02:24:21Z
Releases: 16.0 
Track shared buffer hits in pg_stat_io

Among other things, this should make it easier to calculate a useful cache hit
ratio by excluding buffer reads via buffer access strategies. As buffer access
strategies reuse buffers (and thus evict the prior buffer contents), it is
normal to see reads on repeated scans of the same data.

Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CAAKRu_beMa9Hzih40%3DXPYqhDVz6tsgUGTrhZXRo%3Dunp%2Bszb%3DUA%40mail.gmail.com

Files

PathChange+/−
doc/src/sgml/monitoring.sgml modified +11 −0
src/backend/catalog/system_views.sql modified +1 −0
src/backend/storage/buffer/bufmgr.c modified +14 −24
src/backend/storage/buffer/localbuf.c modified +2 −9
src/backend/utils/activity/pgstat_io.c modified +1 −1
src/backend/utils/adt/pgstatfuncs.c modified +7 −4
src/include/catalog/pg_proc.dat modified +3 −3
src/include/pgstat.h modified +1 −0
src/include/storage/buf_internals.h modified +1 −1
src/test/regress/expected/rules.out modified +2 −1
src/test/regress/expected/stats.out modified +44 −2
src/test/regress/sql/stats.sql modified +22 −2

Documentation touched

Discussion