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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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21
src/backend/nodes/equalfuncs.c
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@@ -18,7 +18,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.180 2003/01/15 19:35:37 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.181 2003/01/20 18:54:46 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -486,6 +486,16 @@ _equalJoinInfo(JoinInfo *a, JoinInfo *b)
return true;
}
static bool
_equalInClauseInfo(InClauseInfo *a, InClauseInfo *b)
{
COMPARE_INTLIST_FIELD(lefthand);
COMPARE_INTLIST_FIELD(righthand);
COMPARE_NODE_FIELD(sub_targetlist);
return true;
}
/*
* Stuff from parsenodes.h
@@ -518,9 +528,9 @@ _equalQuery(Query *a, Query *b)
/*
* We do not check the internal-to-the-planner fields: base_rel_list,
* other_rel_list, join_rel_list, equi_key_list, query_pathkeys,
* hasJoinRTEs. They might not be set yet, and in any case they should
* be derivable from the other fields.
* other_rel_list, join_rel_list, equi_key_list, in_info_list,
* query_pathkeys, hasJoinRTEs. They might not be set yet, and in any
* case they should be derivable from the other fields.
*/
return true;
}
@@ -1618,6 +1628,9 @@ equal(void *a, void *b)
case T_JoinInfo:
retval = _equalJoinInfo(a, b);
break;
case T_InClauseInfo:
retval = _equalInClauseInfo(a, b);
break;
/*
* LIST NODES