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Commit9e38d2a

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Update documentation mention of VACUUM FULL and CLUSTER where
appropriate.Guillaume Cottenceau
1 parentf14f27d commit9e38d2a

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‎doc/src/sgml/maintenance.sgml

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<!-- $PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.74 2007/05/15 15:52:40 neilc Exp $ -->
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<!-- $PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.75 2007/05/30 19:45:00 momjian Exp $ -->
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<chapter id="maintenance">
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<title>Routine Database Maintenance Tasks</title>
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command. This uses a more aggressive algorithm for reclaiming the
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space consumed by dead row versions. Any space that is freed by
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<command>VACUUM FULL</command> is immediately returned to the
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operating system. Unfortunately, this variant of the
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operating system, and the table data is physically compacted on
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the disk. Unfortunately, this variant of the
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<command>VACUUM</command> command acquires an exclusive lock on
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each table while <command>VACUUM FULL</command> is processing
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it. Therefore, frequently using <command>VACUUM FULL</command> can
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<para>
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The standard form of <command>VACUUM</> is best used with the goal
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of maintaining a fairly level steady-state usage of disk space. If
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you need to return disk space to the operating system you can use
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you need to return disk space to the operating system, you can use
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<command>VACUUM FULL</> &mdash; but what's the point of releasing disk
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space that will only have to be allocated again soon? Moderately
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frequent standard <command>VACUUM</> runs are a better approach
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than infrequent <command>VACUUM FULL</> runs for maintaining
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heavily-updated tables.
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heavily-updated tables. However, if some heavily-updated tables
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have gone too long with infrequent <command>VACUUM</>, you can
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use <command>VACUUM FULL</> or <command>CLUSTER</> to get performance
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back (it is much slower to scan a table containing almost only dead
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rows).
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</para>
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<para>

‎doc/src/sgml/ref/vacuum.sgml

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<!--
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$PostgreSQL: pgsql/doc/src/sgml/ref/vacuum.sgml,v 1.47 2007/01/31 23:26:04 momjian Exp $
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$PostgreSQL: pgsql/doc/src/sgml/ref/vacuum.sgml,v 1.48 2007/05/30 19:45:01 momjian Exp $
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PostgreSQL documentation
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-->
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@@ -164,10 +164,11 @@ VACUUM [ FULL ] [ FREEZE ] [ VERBOSE ] ANALYZE [ <replaceable class="PARAMETER">
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<para>
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The <option>FULL</option> option is not recommended for routine use,
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but might be useful in special cases. An example is when you have deleted
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most of the rows in a table and would like the table to physically shrink
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to occupy less disk space. <command>VACUUM FULL</command> will usually
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shrink the table more than a plain <command>VACUUM</command> would.
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The <option>FULL</option> option does not shrink indexes; a periodic
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or updated most of the rows in a table and would like the table to
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physically shrink to occupy less disk space and allow faster table
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scans. <command>VACUUM FULL</command> will usually shrink the table
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more than a plain <command>VACUUM</command> would. The
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<option>FULL</option> option does not shrink indexes; a periodic
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<command>REINDEX</> is still recommended. In fact, it is often faster
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to drop all indexes, <command>VACUUM FULL</>, and recreate the indexes.
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</para>

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