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diff --git a/doc/man/cluster.l b/doc/man/cluster.l new file mode 100644 index 00000000000..a10e83bc2d7 --- /dev/null +++ b/doc/man/cluster.l @@ -0,0 +1,33 @@ +.\" This is -*-nroff-*- +.\" XXX standard disclaimer belongs here.... +.\" $Header: /cvsroot/pgsql/doc/man/Attic/cluster.l,v 1.1.1.1 1996/08/18 22:14:20 scrappy Exp $ +.TH CLUSTER SQL 01/23/93 Postgres95 Postgres95 +.SH NAME +cluster \(em give storage clustering advice to Postgres +.SH SYNOPSIS +.nf +\fBcluster\fR indexname \fBon\fR attname +.fi +.SH DESCRIPTION +This command instructs Postgres to cluster the class specified by +.IR classname +approximately based on the index specified by +.IR indexname. +The index must already have been defined on +.IR classname. +.PP +When a class is clustered, it is physically reordered based on the index +information. The clustering is static. In other words, if the class is +updated, it may become unclustered. No attempt is made to keep new +instances or updated tuples clustered. If desired, the user can +recluster manually by issuing the command again. +.SH EXAMPLE +.nf +/* + * cluster employees in based on its salary attribute + */ +create index emp_ind on emp using btree (salary int4_ops); + +cluster emp_ind on emp +.fi + |