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Restructure planning of nestloop inner indexscans so that the set of usable

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joinclauses is determined accurately for each join.  Formerly, the code only
considered joinclauses that used all of the rels from the outer side of the
join; thus for example
	FROM (a CROSS JOIN b) JOIN c ON (c.f1 = a.x AND c.f2 = b.y)
could not exploit a two-column index on c(f1,f2), since neither of the
qual clauses would be in the joininfo list it looked in.  The new code does
this correctly, and also is able to eliminate redundant clauses, thus fixing
the problem noted 24-Oct-02 by Hans-Jürgen Schönig.
This commit is contained in:
Tom Lane
2002-11-24 21:52:15 +00:00
parent 6bfc09baf4
commit 04c8785c7b
19 changed files with 742 additions and 579 deletions
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42
src/backend/nodes/list.c
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@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/nodes/list.c,v 1.41 2002/06/20 20:29:29 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/nodes/list.c,v 1.42 2002/11/24 21:52:13 tgl Exp $
*
* NOTES
* XXX a few of the following functions are duplicated to handle
@@ -372,6 +372,46 @@ set_unioni(List *l1, List *l2)
return retval;
}
/*
* Generate the intersection of two lists,
* ie, all members of both l1 and l2.
*
* NOTE: if there are duplicates in l1 they will still be duplicate in the
* result; but duplicates in l2 are discarded.
*
* The result is a fresh List, but it points to the same member nodes
* as were in the inputs.
*/
#ifdef NOT_USED
List *
set_intersect(List *l1, List *l2)
{
List *retval = NIL;
List *i;
foreach(i, l1)
{
if (member(lfirst(i), l2))
retval = lappend(retval, lfirst(i));
}
return retval;
}
#endif
List *
set_intersecti(List *l1, List *l2)
{
List *retval = NIL;
List *i;
foreach(i, l1)
{
if (intMember(lfirsti(i), l2))
retval = lappendi(retval, lfirsti(i));
}
return retval;
}
/*
* member()
* nondestructive, returns t iff l1 is a member of the list l2