--- /dev/null
+<!--
+$Header: /cvsroot/pgsql/doc/src/sgml/diskusage.sgml,v 1.1 2002/06/13 05:15:22 momjian Exp $
+-->
+
+<chapter id="diskusage">
+ <title>Monitoring Disk Usage</title>
+
+ <sect1 id="disk-usage">
+ <title>Monitoring Disk Usage</Title>
+
+ <indexterm zone="disk-usage">
+ <primary>disk usage</primary>
+ </indexterm>
+
+ <para>
+ Each table has a primary heap disk file where most of the data is
+ stored. To store long column values, there is also a
+ <acronym>TOAST</> file associated with the table, named based on the
+ table's oid (actually pg_class.relfilenode), and an index on the
+ <acronym>TOAST</> table. There also may be indexes associated with
+ the base table.
+ </para>
+
+ <para>
+ You can monitor disk space from two places; from inside
+ <application>psql</> and from the command line using
+ <application>contrib/oid2name</>. Using <application>psql</> you can
+ issue queries to see the disk usage for any table:
+<programlisting>
+play=# SELECT relfilenode, relpages
+play-# FROM pg_class
+play-# WHERE relname = 'customer';
+ relfilenode | relpages
+-------------+----------
+ 16806 | 60
+(1 row)
+</programlisting>
+ </para>
+
+ <para>
+ Each page is typically 8 kilobytes. <literal>relpages</> is only
+ updated by <command>VACUUM</> and <command>ANALYZE</>. To show the
+ space used by <acronym>TOAST</> tables, use a query based on the heap
+ relfilenode:
+<programlisting>
+play=# SELECT relname, relpages
+play-# FROM pg_class
+play-# WHERE relname = 'pg_toast_16806' or
+play-# relname = 'pg_toast_16806_index'
+play-# ORDER BY relname;
+ relname | relpages
+----------------------+----------
+ pg_toast_16806 | 0
+ pg_toast_16806_index | 1
+</programlisting>
+ </para>
+
+ <para>
+ You can easily display index usage too:
+<programlisting>
+play=# SELECT c2.relname, c2.relpages
+play-# FROM pg_class c, pg_class c2, pg_index i
+play-# WHERE c.relname = 'customer' AND
+play-# c.oid = i.indrelid AND
+play-# c2.oid = i.indexrelid
+play-# ORDER BY c2.relname;
+ relname | relpages
+----------------------+----------
+ customer_id_indexdex | 26
+</programlisting>
+ </para>
+
+ <para>
+ It is easy to find your largest files using <application>psql</>:
+<programlisting>
+play=# SELECT relname, relpages
+play-# FROM pg_class
+play-# ORDER BY relpages DESC;
+ relname | relpages
+----------------------+----------
+ bigtable | 3290
+ customer | 3144
+</programlisting>
+ </para>
+
+ <para>
+ You can also use <application>oid2name</> to show disk usage. See
+ <filename>README.oid2name</> for examples. It includes a script
+ shows disk usage for each database.
+ </para>
+ </sect1>
+</chapter>
+
+<!-- Keep this comment at the end of the file
+Local variables:
+mode:sgml
+sgml-omittag:nil
+sgml-shorttag:t
+sgml-minimize-attributes:nil
+sgml-always-quote-attributes:t
+sgml-indent-step:1
+sgml-indent-data:t
+sgml-parent-document:nil
+sgml-default-dtd-file:"./reference.ced"
+sgml-exposed-tags:nil
+sgml-local-catalogs:("/usr/lib/sgml/catalog")
+sgml-local-ecat-files:nil
+End:
+-->
<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/maintenance.sgml,v 1.13 2002/06/13 04:36:50 momjian Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/maintenance.sgml,v 1.14 2002/06/13 05:15:22 momjian Exp $
-->
<chapter id="maintenance">
</sect2>
</sect1>
- <sect1 id="diskspace-maintenance">
- <title>Disk Space Maintenance</title>
-
- <indexterm zone="diskspace-maintenance">
- <primary>disk space</primary>
- </indexterm>
-
- <para>
- Each table has a primary heap disk file where most of the data is
- stored. To store long column values, there is also a
- <acronym>TOAST</> file associated with the table, named based on the
- table's oid (actually pg_class.relfilenode), and an index on the
- <acronym>TOAST</> table. There also may be indexes associated with
- the base table.
- </para>
-
- <para>
- You can monitor disk space from two places; from inside
- <application>psql</> and from the command line using
- <application>contrib/oid2name</>. Using <application>psql</> you can
- issue queries to see the disk usage for any table:
-<programlisting>
-play=# SELECT relfilenode, relpages
-play-# FROM pg_class
-play-# WHERE relname = 'customer';
- relfilenode | relpages
--------------+----------
- 16806 | 60
-(1 row)
-</programlisting>
- </para>
-
- <para>
- Each page is typically 8 kilobytes. <literal>relpages</> is only
- updated by <command>VACUUM</> and <command>ANALYZE</>. To show the
- space used by <acronym>TOAST</> tables, use a query based on the heap
- relfilenode:
-<programlisting>
-play=# SELECT relname, relpages
-play-# FROM pg_class
-play-# WHERE relname = 'pg_toast_16806' or
-play-# relname = 'pg_toast_16806_index'
-play-# ORDER BY relname;
- relname | relpages
-----------------------+----------
- pg_toast_16806 | 0
- pg_toast_16806_index | 1
-</programlisting>
- </para>
-
- <para>
- You can easily display index usage too:
-<programlisting>
-play=# SELECT c2.relname, c2.relpages
-play-# FROM pg_class c, pg_class c2, pg_index i
-play-# WHERE c.relname = 'customer' AND
-play-# c.oid = i.indrelid AND
-play-# c2.oid = i.indexrelid
-play-# ORDER BY c2.relname;
- relname | relpages
-----------------------+----------
- customer_id_indexdex | 26
-</programlisting>
- </para>
-
- <para>
- It is easy to find your largest files using <application>psql</>:
-<programlisting>
-play=# SELECT relname, relpages
-play-# FROM pg_class
-play-# ORDER BY relpages DESC;
- relname | relpages
-----------------------+----------
- bigtable | 3290
- customer | 3144
-</programlisting>
- </para>
-
- <para>
- You can also use <application>oid2name</> to show disk usage. See
- <filename>README.oid2name</> for examples. It includes a script
- shows disk usage for each database.
- </para>
- </sect1>
-
<sect1 id="logfile-maintenance">
<title>Log File Maintenance</title>
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