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Remove assumptions that not-equals operators cannot be in any opclass.

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get_op_btree_interpretation assumed this in order to save some duplication
of code, but it's not true in general anymore because we added <> support
to btree_gist.  (We still assume it for btree opclasses, though.)

Also, essentially the same logic was baked into predtest.c.  Get rid of
that duplication by generalizing get_op_btree_interpretation so that it
can be used by predtest.c.

Per bug report from Denis de Bernardy and investigation by Jeff Davis,
though I didn't use Jeff's patch exactly as-is.

Back-patch to 9.1; we do not support this usage before that.
This commit is contained in:
Tom Lane
2011-07-06 14:53:16 -04:00
parent c7f23494c1
commit 14f67192c2
4 changed files with 147 additions and 183 deletions
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99
src/backend/utils/cache/lsyscache.c vendored
View File

@ -623,52 +623,30 @@ get_op_hash_functions(Oid opno,
/*
* get_op_btree_interpretation
* Given an operator's OID, find out which btree opfamilies it belongs to,
* and what strategy number it has within each one. The results are
* returned as an OID list and a parallel integer list.
* and what properties it has within each one. The results are returned
* as a palloc'd list of OpBtreeInterpretation structs.
*
* In addition to the normal btree operators, we consider a <> operator to be
* a "member" of an opfamily if its negator is an equality operator of the
* opfamily. ROWCOMPARE_NE is returned as the strategy number for this case.
*/
void
get_op_btree_interpretation(Oid opno, List **opfamilies, List **opstrats)
List *
get_op_btree_interpretation(Oid opno)
{
List *result = NIL;
OpBtreeInterpretation *thisresult;
CatCList *catlist;
bool op_negated;
int i;
*opfamilies = NIL;
*opstrats = NIL;
/*
* Find all the pg_amop entries containing the operator.
*/
catlist = SearchSysCacheList1(AMOPOPID, ObjectIdGetDatum(opno));
/*
* If we can't find any opfamily containing the op, perhaps it is a <>
* operator. See if it has a negator that is in an opfamily.
*/
op_negated = false;
if (catlist->n_members == 0)
{
Oid op_negator = get_negator(opno);
if (OidIsValid(op_negator))
{
op_negated = true;
ReleaseSysCacheList(catlist);
catlist = SearchSysCacheList1(AMOPOPID,
ObjectIdGetDatum(op_negator));
}
}
/* Now search the opfamilies */
for (i = 0; i < catlist->n_members; i++)
{
HeapTuple op_tuple = &catlist->members[i]->tuple;
Form_pg_amop op_form = (Form_pg_amop) GETSTRUCT(op_tuple);
Oid opfamily_id;
StrategyNumber op_strategy;
/* must be btree */
@ -676,23 +654,66 @@ get_op_btree_interpretation(Oid opno, List **opfamilies, List **opstrats)
continue;
/* Get the operator's btree strategy number */
opfamily_id = op_form->amopfamily;
op_strategy = (StrategyNumber) op_form->amopstrategy;
Assert(op_strategy >= 1 && op_strategy <= 5);
if (op_negated)
{
/* Only consider negators that are = */
if (op_strategy != BTEqualStrategyNumber)
continue;
op_strategy = ROWCOMPARE_NE;
}
*opfamilies = lappend_oid(*opfamilies, opfamily_id);
*opstrats = lappend_int(*opstrats, op_strategy);
thisresult = (OpBtreeInterpretation *)
palloc(sizeof(OpBtreeInterpretation));
thisresult->opfamily_id = op_form->amopfamily;
thisresult->strategy = op_strategy;
thisresult->oplefttype = op_form->amoplefttype;
thisresult->oprighttype = op_form->amoprighttype;
result = lappend(result, thisresult);
}
ReleaseSysCacheList(catlist);
/*
* If we didn't find any btree opfamily containing the operator, perhaps
* it is a <> operator. See if it has a negator that is in an opfamily.
*/
if (result == NIL)
{
Oid op_negator = get_negator(opno);
if (OidIsValid(op_negator))
{
catlist = SearchSysCacheList1(AMOPOPID,
ObjectIdGetDatum(op_negator));
for (i = 0; i < catlist->n_members; i++)
{
HeapTuple op_tuple = &catlist->members[i]->tuple;
Form_pg_amop op_form = (Form_pg_amop) GETSTRUCT(op_tuple);
StrategyNumber op_strategy;
/* must be btree */
if (op_form->amopmethod != BTREE_AM_OID)
continue;
/* Get the operator's btree strategy number */
op_strategy = (StrategyNumber) op_form->amopstrategy;
Assert(op_strategy >= 1 && op_strategy <= 5);
/* Only consider negators that are = */
if (op_strategy != BTEqualStrategyNumber)
continue;
/* OK, report it with "strategy" ROWCOMPARE_NE */
thisresult = (OpBtreeInterpretation *)
palloc(sizeof(OpBtreeInterpretation));
thisresult->opfamily_id = op_form->amopfamily;
thisresult->strategy = ROWCOMPARE_NE;
thisresult->oplefttype = op_form->amoplefttype;
thisresult->oprighttype = op_form->amoprighttype;
result = lappend(result, thisresult);
}
ReleaseSysCacheList(catlist);
}
}
return result;
}
/*