提交 08674935 编写于 作者: B Bruce Momjian

Document need for periodic REINDEX in VACUUM FULL cases.

上级 1a628134
<!-- $PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.66 2007/01/16 18:26:02 alvherre Exp $ --> <!-- $PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.67 2007/01/31 04:13:22 momjian Exp $ -->
<chapter id="maintenance"> <chapter id="maintenance">
<title>Routine Database Maintenance Tasks</title> <title>Routine Database Maintenance Tasks</title>
...@@ -615,9 +615,7 @@ analyze threshold = analyze base threshold + analyze scale factor * number of tu ...@@ -615,9 +615,7 @@ analyze threshold = analyze base threshold + analyze scale factor * number of tu
for inefficient use of space: if all but a few index keys on a page have for inefficient use of space: if all but a few index keys on a page have
been deleted, the page remains allocated. So a usage pattern in which all been deleted, the page remains allocated. So a usage pattern in which all
but a few keys in each range are eventually deleted will see poor use of but a few keys in each range are eventually deleted will see poor use of
space. The potential for bloat is not indefinite &mdash; at worst there space. For such usage patterns, periodic reindexing is recommended.
will be one key per page &mdash; but it may still be worthwhile to schedule
periodic reindexing for indexes that have such usage patterns.
</para> </para>
<para> <para>
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$PostgreSQL: pgsql/doc/src/sgml/ref/vacuum.sgml,v 1.45 2006/12/27 14:55:17 momjian Exp $ $PostgreSQL: pgsql/doc/src/sgml/ref/vacuum.sgml,v 1.46 2007/01/31 04:13:22 momjian Exp $
PostgreSQL documentation PostgreSQL documentation
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...@@ -167,6 +167,9 @@ VACUUM [ FULL ] [ FREEZE ] [ VERBOSE ] ANALYZE [ <replaceable class="PARAMETER"> ...@@ -167,6 +167,9 @@ VACUUM [ FULL ] [ FREEZE ] [ VERBOSE ] ANALYZE [ <replaceable class="PARAMETER">
most of the rows in a table and would like the table to physically shrink most of the rows in a table and would like the table to physically shrink
to occupy less disk space. <command>VACUUM FULL</command> will usually to occupy less disk space. <command>VACUUM FULL</command> will usually
shrink the table more than a plain <command>VACUUM</command> would. shrink the table more than a plain <command>VACUUM</command> would.
The <option>FULL</option> option does not shrink indexes; a periodic
<command>REINDEX</> is still recommended. In fact, it is often faster
to drop all indexes, <command>VACUUM FULL</>, and recreate the indexes.
</para> </para>
<para> <para>
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