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Add relallfrozen to pg_class

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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
This commit is contained in:
Melanie Plageman
2025-03-03 11:18:05 -05:00
parent 8492feb98f
commit 99f8f3fbbc
14 changed files with 190 additions and 70 deletions
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20
doc/src/sgml/catalogs.sgml
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@ -2066,6 +2066,26 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
</para></entry>
</row>
<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>