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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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4
src/include/utils/selfuncs.h
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@@ -8,7 +8,7 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: selfuncs.h,v 1.10 2002/11/19 23:22:00 tgl Exp $
* $Id: selfuncs.h,v 1.11 2003/01/20 18:55:07 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -75,7 +75,7 @@ extern void mergejoinscansel(Query *root, Node *clause,
Selectivity *leftscan,
Selectivity *rightscan);
extern double estimate_num_groups(Query *root, List *groupClauses,
extern double estimate_num_groups(Query *root, List *groupExprs,
double input_rows);
extern Datum btcostestimate(PG_FUNCTION_ARGS);