database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-09-02 04:21:28 +03:00
Code Activity

Create functions pg_set_relation_stats, pg_clear_relation_stats.

Browse Source 
These functions are used to tweak statistics on any relation, provided
that the user has MAINTAIN privilege on the relation, or is the database
owner.

Bump catalog version.

Author: Corey Huinker
Discussion: https://postgr.es/m/CADkLM=eErgzn7ECDpwFcptJKOk9SxZEk5Pot4d94eVTZsvj3gw@mail.gmail.com
This commit is contained in:
Jeff Davis
2024-10-11 16:55:11 -07:00
parent 6f782a2a17
commit e839c8ecc9
12 changed files with 700 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

94
doc/src/sgml/func.sgml
View File

@@ -30135,6 +30135,100 @@ DETAIL: Make sure pg_wal_replay_wait() isn't called within a transaction with a
</tgroup>
</table>
<para>
<xref linkend="functions-admin-statsmod"/> lists functions used to
manipulate statistics.
<warning>
<para>
Changes made by these statistics manipulation functions are likely to be
overwritten by <link linkend="autovacuum">autovacuum</link> (or manual
<command>VACUUM</command> or <command>ANALYZE</command>) and should be
considered temporary.
</para>
</warning>
</para>
<table id="functions-admin-statsmod">
<title>Database Object Statistics Manipulation Functions</title>
<tgroup cols="1">
<thead>
<row>
<entry role="func_table_entry"><para role="func_signature">
Function
</para>
<para>
Description
</para></entry>
</row>
</thead>
<tbody>
<row>
<entry role="func_table_entry">
<para role="func_signature">
<indexterm>
<primary>pg_set_relation_stats</primary>
</indexterm>
<function>pg_set_relation_stats</function> (
<parameter>relation</parameter> <type>regclass</type>
<optional>, <parameter>relpages</parameter> <type>integer</type></optional>
<optional>, <parameter>reltuples</parameter> <type>real</type></optional>
<optional>, <parameter>relallvisible</parameter> <type>integer</type></optional> )
<returnvalue>boolean</returnvalue>
</para>
<para>
Updates relation-level statistics for the given relation to the
specified values. The parameters correspond to columns in <link
linkend="catalog-pg-class"><structname>pg_class</structname></link>. Unspecified
or <literal>NULL</literal> values leave the setting
unchanged. Returns <literal>true</literal> if a change was made;
<literal>false</literal> otherwise.
</para>
<para>
Ordinarily, these statistics are collected automatically or updated
as a part of <xref linkend="sql-vacuum"/> or <xref
linkend="sql-analyze"/>, so it's not necessary to call this
function. However, it may be useful when testing the effects of
statistics on the planner to understand or anticipate plan changes.
</para>
<para>
The caller must have the <literal>MAINTAIN</literal> privilege on
the table or be the owner of the database.
</para>
<para>
The value of <structfield>relpages</structfield> must be greater than
or equal to <literal>0</literal>,
<structfield>reltuples</structfield> must be greater than or equal to
<literal>-1.0</literal>, and <structfield>relallvisible</structfield>
must be greater than or equal to <literal>0</literal>.
</para>
</entry>
</row>
<row>
<entry role="func_table_entry">
<para role="func_signature">
<indexterm>
<primary>pg_clear_relation_stats</primary>
</indexterm>
<function>pg_clear_relation_stats</function> ( <parameter>relation</parameter> <type>regclass</type> )
<returnvalue>boolean</returnvalue>
</para>
<para>
Clears table-level statistics for the given relation, as though the
table was newly created. Returns <literal>true</literal> if a change
was made; <literal>false</literal> otherwise.
</para>
<para>
The caller must have the <literal>MAINTAIN</literal> privilege on
the table or be the owner of the database.
</para>
</entry>
</row>
</tbody>
</tgroup>
</table>
<para>
<xref linkend="functions-info-partition"/> lists functions that provide
information about the structure of partitioned tables.