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Implement SEMI and ANTI joins in the planner and executor. (Semijoins replace

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the old JOIN_IN code, but antijoins are new functionality.)  Teach the planner
to convert appropriate EXISTS and NOT EXISTS subqueries into semi and anti
joins respectively.  Also, LEFT JOINs with suitable upper-level IS NULL
filters are recognized as being anti joins.  Unify the InClauseInfo and
OuterJoinInfo infrastructure into "SpecialJoinInfo".  With that change,
it becomes possible to associate a SpecialJoinInfo with every join attempt,
which permits some cleanup of join selectivity estimation.  That needs to be
taken much further than this patch does, but the next step is to change the
API for oprjoin selectivity functions, which seems like material for a
separate patch.  So for the moment the output size estimates for semi and
especially anti joins are quite bogus.
This commit is contained in:
Tom Lane
2008-08-14 18:48:00 +00:00
parent ef1c807c25
commit e006a24ad1
40 changed files with 2129 additions and 1204 deletions
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4
src/include/optimizer/prep.h
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@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/optimizer/prep.h,v 1.60 2008/03/18 22:04:14 tgl Exp $
* $PostgreSQL: pgsql/src/include/optimizer/prep.h,v 1.61 2008/08/14 18:48:00 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -21,7 +21,7 @@
/*
* prototypes for prepjointree.c
*/
extern Node *pull_up_IN_clauses(PlannerInfo *root, Node *node);
extern Node *pull_up_sublinks(PlannerInfo *root, Node *node);
extern void inline_set_returning_functions(PlannerInfo *root);
extern Node *pull_up_subqueries(PlannerInfo *root, Node *jtnode,
bool below_outer_join, bool append_rel_member);