documentation for HAVING, clean up UNION comment.

This commit is contained in:
Bruce Momjian 1998-03-30 19:05:10 +00:00
parent ef0eecfa1f
commit 01ecb2e3a0
3 changed files with 27 additions and 7 deletions

View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.20 1998/02/26 04:33:05 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.21 1998/03/30 19:04:41 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -71,7 +71,8 @@ plan_union_queries(Query *parse)
union_found = false,
last_unionall_flag = false;
/*
/*------------------------------------------------------------------
*
* Do we need to split up our unions because we have UNION and UNION
* ALL?
*
@ -87,10 +88,25 @@ plan_union_queries(Query *parse)
*
* So the above query becomes:
*
* Append Node { Sort and Unique { Append Node { SELECT 1
* This is really a sub-UNION, unionClause We run a
* DISTINCT on these. { SELECT 2 SELECT 3 } } } SELECT 4 SELECT 5 }
* Append Node
* {
* Sort and Unique
* {
* Append Node
* {
* SELECT 1 This is really a sub-UNION.
* unionClause We run a DISTINCT on these.
* {
* SELECT 2
* SELECT 3
* }
* }
* }
* SELECT 4
* SELECT 5
* }
*
*---------------------------------------------------------------------
*/
foreach(ulist, parse->unionClause)

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@ -5,7 +5,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: psqlHelp.h,v 1.41 1998/03/18 15:48:26 momjian Exp $
* $Id: psqlHelp.h,v 1.42 1998/03/30 19:04:53 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -163,6 +163,7 @@ static struct _helpStruct QL_HELP[] = {
\t[from <from_list>]\n\
\t[where <qual>]\n\
\t[group by <group_list>]\n\
\t[having <having_clause>]\n\
\t[order by <attr1> [using <op1>],... <attrN> [using <opN>]]\n\
\t[union [all] select ...];"},
{"delete",
@ -243,6 +244,7 @@ static struct _helpStruct QL_HELP[] = {
\t[from <from_clause>]\n\
\t[where <qual>]\n\
\t[group by <group_list>]\n\
\t[having <having_clause>]\n\
\t[union [all] select ...];"},
{"listen",
"listen for notification on a relation",
@ -277,6 +279,7 @@ static struct _helpStruct QL_HELP[] = {
\t[from <from_list>]\n\
\t[where <qual>]\n\
\t[group by <group_list>]\n\
\t[having <having_clause>]\n\
\t[order by <attr1> [ASC | DESC] [using <op1>], ... <attrN> ]\n\
\t[union [all] select ...];"},
{"set",

View File

@ -1,6 +1,6 @@
.\" This is -*-nroff-*-
.\" XXX standard disclaimer belongs here....
.\" $Header: /cvsroot/pgsql/src/man/Attic/select.l,v 1.5 1998/03/18 15:49:08 momjian Exp $
.\" $Header: /cvsroot/pgsql/src/man/Attic/select.l,v 1.6 1998/03/30 19:05:10 momjian Exp $
.TH SELECT SQL 11/05/95 PostgreSQL PostgreSQL
.SH NAME
select - retrieve instances from a class
@ -13,6 +13,7 @@ select - retrieve instances from a class
[\fBfrom\fR from-list]
[\fBwhere\fR where-clause]
[\fBgroup by\fR attr_name1 {, attr_name-i....}]
[\fBhaving\fR having-clause]
[\fBorder by\fR attr_name1 [\fBasc\fR | \fBdesc\fR] [\fBusing op1\fR] {, attr_namei...}]
[\fBunion {all} select\fR ...]