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| author | Melanie Plageman <melanieplageman@gmail.com> | 2025-03-03 11:18:05 -0500 |
|---|---|---|
| committer | Melanie Plageman <melanieplageman@gmail.com> | 2025-03-03 11:18:05 -0500 |
| commit | 99f8f3fbbc8f743290844e8c676d39dad11c5d5d (patch) | |
| tree | bfa0507e88c83d28053a7e8beb36d8d61b43b871 /doc/src | |
| parent | 8492feb98f6df3f0f03e84ed56f0d1cbb2ac514c (diff) | |
| download | postgresql-99f8f3fbbc8f743290844e8c676d39dad11c5d5d.tar.gz postgresql-99f8f3fbbc8f743290844e8c676d39dad11c5d5d.zip | |
Add relallfrozen to pg_class
Add relallfrozen, an estimate of the number of pages marked all-frozen
in the visibility map.
pg_class already has relallvisible, an estimate of the number of pages
in the relation marked all-visible in the visibility map. This is used
primarily for planning.
relallfrozen, together with relallvisible, is useful for estimating the
outstanding number of all-visible but not all-frozen pages in the
relation for the purposes of scheduling manual VACUUMs and tuning vacuum
freeze parameters.
A future commit will use relallfrozen to trigger more frequent vacuums
on insert-focused workloads with significant volume of frozen data.
Bump catalog version
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Robert Treat <rob@xzilla.net>
Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Reviewed-by: Greg Sabino Mullane <htamfids@gmail.com>
Discussion: https://postgr.es/m/flat/CAAKRu_aj-P7YyBz_cPNwztz6ohP%2BvWis%3Diz3YcomkB3NpYA--w%40mail.gmail.com
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/catalogs.sgml | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml index ee59a7e15d0..9a21a0d6f15 100644 --- a/doc/src/sgml/catalogs.sgml +++ b/doc/src/sgml/catalogs.sgml @@ -2068,6 +2068,26 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l <row> <entry role="catalog_table_entry"><para role="column_definition"> + <structfield>relallfrozen</structfield> <type>int4</type> + </para> + <para> + Number of pages that are marked all-frozen in the table's visibility + map. This is only an estimate and can be used along with + <structfield>relallvisible</structfield> for scheduling vacuums and + tuning <link linkend="runtime-config-vacuum-freezing">vacuum's freezing + behavior</link>. + + It is updated by + <link linkend="sql-vacuum"><command>VACUUM</command></link>, + <link linkend="sql-analyze"><command>ANALYZE</command></link>, + and a few DDL commands such as + <link linkend="sql-createindex"><command>CREATE INDEX</command></link>. + </para></entry> + </row> + + + <row> + <entry role="catalog_table_entry"><para role="column_definition"> <structfield>reltoastrelid</structfield> <type>oid</type> (references <link linkend="catalog-pg-class"><structname>pg_class</structname></link>.<structfield>oid</structfield>) </para> |