Skip to content
Snippets Groups Projects
Commit 7c6bac00 authored by Bruce Momjian's avatar Bruce Momjian
Browse files

Update vacuum to mention analyze

parent a7b1ff66
No related branches found
No related tags found
No related merge requests found
<!-- <!--
$Header: /cvsroot/pgsql/doc/src/sgml/ref/vacuum.sgml,v 1.7 1999/12/07 22:41:41 momjian Exp $ $Header: /cvsroot/pgsql/doc/src/sgml/ref/vacuum.sgml,v 1.8 2000/04/05 21:51:11 momjian Exp $
Postgres documentation Postgres documentation
--> -->
...@@ -51,8 +51,6 @@ VACUUM [ VERBOSE ] ANALYZE [ <replaceable class="PARAMETER">table</replaceable> ...@@ -51,8 +51,6 @@ VACUUM [ VERBOSE ] ANALYZE [ <replaceable class="PARAMETER">table</replaceable>
<para> <para>
Updates column statistics used by the optimizer to Updates column statistics used by the optimizer to
determine the most efficient way to execute a query. determine the most efficient way to execute a query.
The statistics represent the disbursion of the data in each column.
This information is valuable when several execution paths are possible.
</para> </para>
</listitem> </listitem>
</varlistentry> </varlistentry>
...@@ -158,6 +156,13 @@ NOTICE: Index <replaceable class="PARAMETER">index</replaceable>: Pages 28; ...@@ -158,6 +156,13 @@ NOTICE: Index <replaceable class="PARAMETER">index</replaceable>: Pages 28;
tuples and number of pages stored in all classes. tuples and number of pages stored in all classes.
</para> </para>
<para>
<command>VACUUM ANALYZE</command> collects statistics representing the
disbursion of the data in each column.
This information is valuable when several query execution paths are possible.
</para>
<para> <para>
Running <command>VACUUM</command> Running <command>VACUUM</command>
periodically will increase the speed of the database in processing user queries. periodically will increase the speed of the database in processing user queries.
...@@ -179,11 +184,12 @@ NOTICE: Index <replaceable class="PARAMETER">index</replaceable>: Pages 28; ...@@ -179,11 +184,12 @@ NOTICE: Index <replaceable class="PARAMETER">index</replaceable>: Pages 28;
query may be executed at any time, however. In particular, after query may be executed at any time, however. In particular, after
copying a large class into <productname>Postgres</productname> copying a large class into <productname>Postgres</productname>
or after deleting a large number of or after deleting a large number of
records, it may be a good idea to issue a <command>VACUUM</command> records, it may be a good idea to issue a <command>VACUUM ANALYZE</command>
query. This will update the system catalogs with the results of all query. This will update the system catalogs with the results of all
recent changes, and allow the <productname>Postgres</productname> recent changes, and allow the <productname>Postgres</productname>
query optimizer to make better choices in planning user queries. query optimizer to make better choices in planning user queries.
</para> </para>
</refsect2> </refsect2>
</refsect1> </refsect1>
......
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment