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IN clauses appearing at top level of WHERE can now be handled as joins.

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There are two implementation techniques: the executor understands a new
JOIN_IN jointype, which emits at most one matching row per left-hand row,
or the result of the IN's sub-select can be fed through a DISTINCT filter
and then joined as an ordinary relation.
Along the way, some minor code cleanup in the optimizer; notably, break
out most of the jointree-rearrangement preprocessing in planner.c and
put it in a new file prep/prepjointree.c.
This commit is contained in:
Tom Lane
2003-01-20 18:55:07 +00:00
parent be2b660ecd
commit bdfbfde1b1
47 changed files with 2075 additions and 875 deletions
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12
src/include/optimizer/prep.h
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@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: prep.h,v 1.33 2002/08/29 16:03:49 tgl Exp $
* $Id: prep.h,v 1.34 2003/01/20 18:55:05 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -17,6 +17,16 @@
#include "nodes/parsenodes.h"
#include "nodes/plannodes.h"
/*
* prototypes for prepjointree.c
*/
extern Node *pull_up_IN_clauses(Query *parse, Node *node);
extern Node *pull_up_subqueries(Query *parse, Node *jtnode,
bool below_outer_join);
extern Node *preprocess_jointree(Query *parse, Node *jtnode);
extern List *get_relids_in_jointree(Node *jtnode);
extern List *get_relids_for_join(Query *parse, int joinrelid);
/*
* prototypes for prepqual.c
*/