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New version attached. The following is implemented:

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- CLUSTER ALL clusters all the tables that have some index with
  indisclustered set and the calling user owns.
- CLUSTER tablename clusters the named table, using the index with
  indisclustered set.  If no index has the bit set, throws elog(ERROR).
- The multi-relation version (CLUSTER ALL) uses a multitransaction
  approach, similar to what VACUUM does.

Alvaro Herrera
This commit is contained in:
Bruce Momjian
2002-11-15 03:09:39 +00:00
parent 5b7eb4dd45
commit 8bc717cb88
8 changed files with 484 additions and 38 deletions
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41
doc/src/sgml/ref/cluster.sgml
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@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/ref/cluster.sgml,v 1.20 2002/09/21 18:32:54 petere Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/ref/cluster.sgml,v 1.21 2002/11/15 03:09:35 momjian Exp $
PostgreSQL documentation
-->
@ -22,6 +22,8 @@ PostgreSQL documentation
</refsynopsisdivinfo>
<synopsis>
CLUSTER <replaceable class="PARAMETER">indexname</replaceable> ON <replaceable class="PARAMETER">tablename</replaceable>
CLUSTER <replaceable class="PARAMETER">tablename</replaceable>
CLUSTER ALL
</synopsis>
<refsect2 id="R2-SQL-CLUSTER-1">
@ -104,6 +106,20 @@ CLUSTER
periodically re-cluster by issuing the command again.
</para>
<para>
When a table is clustered, <productname>PostgreSQL</productname>
remembers on which index it was clustered. In calls to
<command>CLUSTER <replaceable class="parameter">tablename</replaceable></command>,
the table is clustered on the same index that it was clustered before.
</para>
<para>
In calls to <command>CLUSTER ALL</command>, all the tables in the database
that the calling user owns are clustered using the saved information. This
form of <command>CLUSTER</command> cannot be called from inside a
transaction or function.
</para>
<refsect2 id="R2-SQL-CLUSTER-3">
<refsect2info>
<date>1998-09-08</date>
@ -141,8 +157,15 @@ CLUSTER
</para>
<para>
CLUSTER preserves GRANT, inheritance, index, foreign key, and other
ancillary information about the table.
<command>CLUSTER</command> preserves GRANT, inheritance, index, foreign
key, and other ancillary information about the table.
</para>
<para>
Because <command>CLUSTER</command> remembers the clustering information,
one can cluster the tables one wants clustered manually the first time, and
setup a timed event similar to <command>VACUUM</command> so that the tables
are periodically and automatically clustered.
</para>
<para>
@ -192,6 +215,18 @@ SELECT <replaceable class="parameter">columnlist</replaceable> INTO TABLE <repla
<programlisting>
CLUSTER emp_ind ON emp;
</programlisting>
<para>
Cluster the employees relation using the same index that was used before:
</para>
<programlisting>
CLUSTER emp;
</programlisting>
<para>
Cluster all the tables on the database that have previously been clustered:
</para>
<programlisting>
CLUSTER ALL;
</programlisting>
</refsect1>
<refsect1 id="R1-SQL-CLUSTER-3">