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Allow row comparisons to be used as indexscan qualifications.

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This completes the project to upgrade our handling of row comparisons.
This commit is contained in:
Tom Lane
2006-01-25 20:29:24 +00:00
parent 06d45e485d
commit 3a0a16cb7e
11 changed files with 996 additions and 142 deletions
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73
src/backend/optimizer/util/clauses.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.205 2005/12/28 01:30:00 tgl Exp $
* $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.206 2006/01/25 20:29:23 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@ -1167,12 +1167,12 @@ NumRelids(Node *clause)
}
/*
* CommuteClause: commute a binary operator clause
* CommuteOpExpr: commute a binary operator clause
*
* XXX the clause is destructively modified!
*/
void
CommuteClause(OpExpr *clause)
CommuteOpExpr(OpExpr *clause)
{
Oid opoid;
Node *temp;
@ -1200,6 +1200,73 @@ CommuteClause(OpExpr *clause)
lsecond(clause->args) = temp;
}
/*
* CommuteRowCompareExpr: commute a RowCompareExpr clause
*
* XXX the clause is destructively modified!
*/
void
CommuteRowCompareExpr(RowCompareExpr *clause)
{
List *newops;
List *temp;
ListCell *l;
/* Sanity checks: caller is at fault if these fail */
if (!IsA(clause, RowCompareExpr))
elog(ERROR, "expected a RowCompareExpr");
/* Build list of commuted operators */
newops = NIL;
foreach(l, clause->opnos)
{
Oid opoid = lfirst_oid(l);
opoid = get_commutator(opoid);
if (!OidIsValid(opoid))
elog(ERROR, "could not find commutator for operator %u",
lfirst_oid(l));
newops = lappend_oid(newops, opoid);
}
/*
* modify the clause in-place!
*/
switch (clause->rctype)
{
case ROWCOMPARE_LT:
clause->rctype = ROWCOMPARE_GT;
break;
case ROWCOMPARE_LE:
clause->rctype = ROWCOMPARE_GE;
break;
case ROWCOMPARE_GE:
clause->rctype = ROWCOMPARE_LE;
break;
case ROWCOMPARE_GT:
clause->rctype = ROWCOMPARE_LT;
break;
default:
elog(ERROR, "unexpected RowCompare type: %d",
(int) clause->rctype);
break;
}
clause->opnos = newops;
/*
* Note: we don't bother to update the opclasses list, but just set
* it to empty. This is OK since this routine is currently only used
* for index quals, and the index machinery won't use the opclass
* information. The original opclass list is NOT valid if we have
* commuted any cross-type comparisons, so don't leave it in place.
*/
clause->opclasses = NIL; /* XXX */
temp = clause->largs;
clause->largs = clause->rargs;
clause->rargs = temp;
}
/*
* strip_implicit_coercions: remove implicit coercions at top level of tree
*