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We have multi-column indexes, so update manual.

This commit is contained in:
Bruce Momjian 1997-10-30 18:41:03 +00:00
parent ef1fc0c90d
commit 65c00f7e80
1 changed files with 2 additions and 9 deletions
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src/man/create_index.l
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@ -1,6 +1,6 @@
.\" This is -*-nroff-*-
.\" XXX standard disclaimer belongs here....
.\" $Header: /cvsroot/pgsql/src/man/Attic/create_index.l,v 1.6 1997/05/14 01:38:34 vadim Exp $
.\" $Header: /cvsroot/pgsql/src/man/Attic/create_index.l,v 1.7 1997/10/30 18:41:03 momjian Exp $
.TH "CREATE INDEX" SQL 11/05/95 PostgreSQL PostgreSQL
.SH NAME
create index \(em construct a secondary index
@ -44,14 +44,7 @@ result of a user-defined function
.IR funcname
applied to one or more attributes of a single class. These
.IR "functional indices"
are primarily useful in two situations. First, functional indices can
be used to simulate multi-key indices. That is, the user can define a
new base type (a simple combination of, say, \*(lqoid\*(rq and
\*(lqint2\*(rq) and the associated functions and operators on this new
type such that the access method can use it. Once this has been done,
the standard techniques for interfacing new types to access methods
(described in the Postgres user manual) can be applied. Second,
functional indices can be used to obtain fast access to data based on
can be used to obtain fast access to data based on
operators that would normally require some transformation to be
applied to the base data. For example, say you have an attribute in
class \*(lqmyclass\*(rq called \*(lqpt\*(rq that consists of a 2D