database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-16 15:02:33 +03:00
Code Activity

Restructure representation of join alias variables. An explicit JOIN

Browse Source 
now has an RTE of its own, and references to its outputs now are Vars
referencing the JOIN RTE, rather than CASE-expressions.  This allows
reverse-listing in ruleutils.c to use the correct alias easily, rather
than painfully reverse-engineering the alias namespace as it used to do.
Also, nested FULL JOINs work correctly, because the result of the inner
joins are simple Vars that the planner can cope with.  This fixes a bug
reported a couple times now, notably by Tatsuo on 18-Nov-01.  The alias
Vars are expanded into COALESCE expressions where needed at the very end
of planning, rather than during parsing.
Also, beginnings of support for showing plan qualifier expressions in
EXPLAIN.  There are probably still cases that need work.
initdb forced due to change of stored-rule representation.
This commit is contained in:
Tom Lane
2002-03-12 00:52:10 +00:00
parent 66b6bf67a1
commit 6eeb95f0f5
41 changed files with 1950 additions and 996 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
src/include/nodes/primnodes.h
View File

@@ -10,7 +10,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: primnodes.h,v 1.57 2001/11/05 17:46:34 momjian Exp $
* $Id: primnodes.h,v 1.58 2002/03/12 00:52:02 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -513,10 +513,9 @@ typedef struct RangeTblRef
* alias has a critical impact on semantics, because a join with an alias
* restricts visibility of the tables/columns inside it.
*
* During parse analysis, colnames is filled with a list of String nodes
* giving the column names (real or alias) of the output of the join,
* and colvars is filled with a list of expressions that can be copied to
* reference the output columns.
* During parse analysis, an RTE is created for the Join, and its index
* is filled into rtindex. This RTE is present mainly so that Vars can
* be created that refer to the outputs of the join.
*----------
*/
typedef struct JoinExpr
@@ -529,9 +528,7 @@ typedef struct JoinExpr
List *using; /* USING clause, if any (list of String) */
Node *quals; /* qualifiers on join, if any */
struct Attr *alias; /* user-written alias clause, if any */
List *colnames; /* output column names (list of String) */
List *colvars; /* output column nodes (list of
* expressions) */
int rtindex; /* RT index assigned for join */
} JoinExpr;
/*----------