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authorAndres Freund2023-03-31 02:22:40 +0000
committerAndres Freund2023-03-31 02:24:21 +0000
commit8aaa04b32d790da595684de58ae4fc2db96becff (patch)
treed9993491ee35f81fbf8be407a4ef76b486768ef0 /doc/src
parent6c3b697b19db6274da622cf0fe7a7ad32eeeced3 (diff)
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 <[email protected]> Reviewed-by: Bertrand Drouvot <[email protected]> Reviewed-by: Andres Freund <[email protected]> Discussion: https://postgr.es/m/CAAKRu_beMa9Hzih40%3DXPYqhDVz6tsgUGTrhZXRo%3Dunp%2Bszb%3DUA%40mail.gmail.com
Diffstat (limited to 'doc/src')
-rw-r--r--doc/src/sgml/monitoring.sgml11
1 files changed, 11 insertions, 0 deletions
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index c809ff1ba4..d5a45f996d 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -3858,6 +3858,17 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
<row>
<entry role="catalog_table_entry">
<para role="column_definition">
+ <structfield>hits</structfield> <type>bigint</type>
+ </para>
+ <para>
+ The number of times a desired block was found in a shared buffer.
+ </para>
+ </entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry">
+ <para role="column_definition">
<structfield>evictions</structfield> <type>bigint</type>
</para>
<para>