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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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13
src/backend/optimizer/plan/initsplan.c
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@@ -8,13 +8,12 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/initsplan.c,v 1.81 2003/01/15 19:35:40 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/initsplan.c,v 1.82 2003/01/20 18:54:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_type.h"
#include "nodes/makefuncs.h"
@@ -579,6 +578,11 @@ distribute_qual_to_rels(Query *root, Node *clause,
* the appropriate joininfo list (creating a new list and adding it to the
* appropriate rel node if necessary).
*
* Note that the same copy of the restrictinfo node is linked to by all the
* lists it is in. This allows us to exploit caching of information about
* the restriction clause (but we must be careful that the information does
* not depend on context).
*
* 'restrictinfo' describes the join clause
* 'join_relids' is the list of relations participating in the join clause
*/
@@ -602,12 +606,13 @@ add_join_info_to_rels(Query *root, RestrictInfo *restrictinfo,
if (lfirsti(otherrel) != cur_relid)
unjoined_relids = lappendi(unjoined_relids, lfirsti(otherrel));
}
Assert(unjoined_relids != NIL);
/*
* Find or make the joininfo node for this combination of rels,
* and add the restrictinfo node to it.
*/
joininfo = find_joininfo_node(find_base_rel(root, cur_relid),
joininfo = make_joininfo_node(find_base_rel(root, cur_relid),
unjoined_relids);
joininfo->jinfo_restrictinfo = lappend(joininfo->jinfo_restrictinfo,
restrictinfo);
@@ -731,7 +736,7 @@ exprs_known_equal(Query *root, Node *item1, Node *item2)
{
JoinInfo *joininfo = find_joininfo_node(rel1, relids);
restrictlist = joininfo->jinfo_restrictinfo;
restrictlist = joininfo ? joininfo->jinfo_restrictinfo : NIL;
}
/*