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Add ONLY support for VACUUM and ANALYZE

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Since autovacuum does not trigger an ANALYZE for partitioned tables,
users must perform these manually.  However, performing a manual ANALYZE
on a partitioned table would always result in recursively analyzing each
partition and that could be undesirable as autovacuum takes care of that.
For partitioned tables that contain a large number of partitions, having
to analyze each partition could take an unreasonably long time, especially
so for tables with a large number of columns.

Here we allow the ONLY keyword to prefix the name of the table to allow
users to have ANALYZE skip processing partitions.  This option can also
be used with VACUUM, but there is no work to do if VACUUM ONLY is used on
a partitioned table.

This commit also changes the behavior of VACUUM	and ANALYZE for
inheritance parents.  Previously inheritance child tables would not be
processed when operating on the parent.  Now, by default we *do* operate
on the child tables.  ONLY can be used to obtain the old behavior.
The release notes should note this as an incompatibility.  The default
behavior has not changed for partitioned tables as these always
recursively processed the partitions.

Author: Michael Harris <harmic@gmail.com>
Discussion: https://postgr.es/m/CADofcAWATx_haD=QkSxHbnTsAe6+e0Aw8Eh4H8cXyogGvn_kOg@mail.gmail.com
Discussion: https://postgr.es/m/CADofcAXVbD0yGp_EaC9chmzsOoSai3jcfBCnyva3j0RRdRvMVA@mail.gmail.com
Reviewed-by: Jelte Fennema-Nio <postgres@jeltef.nl>
Reviewed-by: Melih Mutlu <m.melihmutlu@gmail.com>
Reviewed-by: Atsushi Torikoshi <torikoshia@oss.nttdata.com>
Reviewed-by: jian he <jian.universality@gmail.com>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
This commit is contained in:
David Rowley
2024-09-24 18:03:40 +12:00
parent bbba59e69a
commit 62ddf7ee9a
8 changed files with 230 additions and 45 deletions
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36
doc/src/sgml/ref/analyze.sgml
View File

@@ -31,7 +31,7 @@ ANALYZE [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] [ <r
<phrase>and <replaceable class="parameter">table_and_columns</replaceable> is:</phrase>
<replaceable class="parameter">table_name</replaceable> [ ( <replaceable class="parameter">column_name</replaceable> [, ...] ) ]
[ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] [ ( <replaceable class="parameter">column_name</replaceable> [, ...] ) ]
</synopsis>
</refsynopsisdiv>
@@ -142,9 +142,12 @@ ANALYZE [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] [ <r
The name (possibly schema-qualified) of a specific table to
analyze. If omitted, all regular tables, partitioned tables, and
materialized views in the current database are analyzed (but not
foreign tables). If the specified table is a partitioned table, both the
inheritance statistics of the partitioned table as a whole and
statistics of the individual partitions are updated.
foreign tables). If <literal>ONLY</literal> is specified before
the table name, only that table is analyzed. If <literal>ONLY</literal>
is not specified, the table and all its inheritance child tables or
partitions (if any) are analyzed. Optionally, <literal>*</literal>
can be specified after the table name to explicitly indicate that
inheritance child tables (or partitions) are to be analyzed.
</para>
</listitem>
</varlistentry>
@@ -284,22 +287,23 @@ ANALYZE [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] [ <r
<command>ANALYZE</command> gathers two sets of statistics: one on the rows
of the parent table only, and a second including rows of both the parent
table and all of its children. This second set of statistics is needed when
planning queries that process the inheritance tree as a whole. The child
tables themselves are not individually analyzed in this case.
The autovacuum daemon, however, will only consider inserts or
updates on the parent table itself when deciding whether to trigger an
automatic analyze for that table. If that table is rarely inserted into
or updated, the inheritance statistics will not be up to date unless you
run <command>ANALYZE</command> manually.
planning queries that process the inheritance tree as a whole. The
autovacuum daemon, however, will only consider inserts or updates on the
parent table itself when deciding whether to trigger an automatic analyze
for that table. If that table is rarely inserted into or updated, the
inheritance statistics will not be up to date unless you run
<command>ANALYZE</command> manually. By default,
<command>ANALYZE</command> will also recursively collect and update the
statistics for each inheritance child table. The <literal>ONLY</literal>
keyword may be used to disable this.
</para>
<para>
For partitioned tables, <command>ANALYZE</command> gathers statistics by
sampling rows from all partitions; in addition, it will recurse into each
partition and update its statistics. Each leaf partition is analyzed only
once, even with multi-level partitioning. No statistics are collected for
only the parent table (without data from its partitions), because with
partitioning it's guaranteed to be empty.
sampling rows from all partitions. By default,
<command>ANALYZE</command> will also recursively collect and update the
statistics for each partition. The <literal>ONLY</literal> keyword may be
used to disable this.
</para>
<para>

11
doc/src/sgml/ref/vacuum.sgml
View File

@@ -42,7 +42,7 @@ VACUUM [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] [ <re
<phrase>and <replaceable class="parameter">table_and_columns</replaceable> is:</phrase>
<replaceable class="parameter">table_name</replaceable> [ ( <replaceable class="parameter">column_name</replaceable> [, ...] ) ]
[ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] [ ( <replaceable class="parameter">column_name</replaceable> [, ...] ) ]
</synopsis>
</refsynopsisdiv>
@@ -401,8 +401,13 @@ VACUUM [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] [ <re
<listitem>
<para>
The name (optionally schema-qualified) of a specific table or
materialized view to vacuum. If the specified table is a partitioned
table, all of its leaf partitions are vacuumed.
materialized view to vacuum. If <literal>ONLY</literal> is specified
before the table name, only that table is vacuumed. If
<literal>ONLY</literal> is not specified, the table and all its
inheritance child tables or partitions (if any) are also vacuumed.
Optionally, <literal>*</literal> can be specified after the table name
to explicitly indicate that inheritance child tables (or partitions) are
to be vacuumed.
</para>
</listitem>
</varlistentry>