46 lines
1.3 KiB
Plaintext
46 lines
1.3 KiB
Plaintext
.\" This is -*-nroff-*-
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.\" XXX standard disclaimer belongs here....
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.\" $Header: /cvsroot/pgsql/doc/man/Attic/create_view.l,v 1.1.1.1 1996/08/18 22:14:22 scrappy Exp $
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.TH "CREATE VIEW" SQL 11/05/95 Postgres95 Postgres95
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.SH NAME
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create view \(em construct a virtual class
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.SH SYNOPSIS
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.nf
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\fBcreate view\fR view_name \fBas\fR
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\fBselect\fR expression1 [\fBas\fR attr_name1]
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{, expression_i [\fBas\fR attr_namei]}
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[\fBfrom\fR from.last]
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[\fBwhere\fR qual]
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.fi
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.SH DESCRIPTION
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.BR "create view"
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will define a view of a class. This view is not physically
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materialized; instead the rule system is used to support view
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processing as in [STON90]. Specifically, a query rewrite retrieve
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rule is automatically generated to support retrieve operations on
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views. Then, the user can add as many update rules as desired to
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specify the processing of update operations to views. See [STON90]
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for a detailed discussion of this point.
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.SH EXAMPLE
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.nf
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--
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--create a view consisting of toy department employees
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--
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create view toyemp as
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select e.name
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from emp e
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where e.dept = 'toy'
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.fi
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.nf
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--
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--Specify deletion semantics for toyemp
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--
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create rule example1 as
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on delete to toyemp
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do instead delete emp
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where emp.oid = current.oid
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.fi
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.SH "SEE ALSO"
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create table(l),
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create rule(l),
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