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Enable btree_predicate_proof() to make proofs involving cross-data-type 

predicate operators.  The hard stuff turns out to be already done in the
previous commit, we need merely open the floodgates...
This commit is contained in:
Tom Lane 2006-12-28 19:53:05 +00:00
parent 91868e7df0
commit c99ddfc43d
1 changed files with 5 additions and 15 deletions
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20
src/backend/optimizer/util/predtest.c
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@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/optimizer/util/predtest.c,v 1.11 2006/12/23 00:43:11 tgl Exp $
* $PostgreSQL: pgsql/src/backend/optimizer/util/predtest.c,v 1.12 2006/12/28 19:53:05 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -1131,7 +1131,7 @@ static const StrategyNumber BT_refute_table[6][6] = {
};
/*----------
/*
* btree_predicate_proof
* Does the predicate implication or refutation test for a "simple clause"
* predicate and a "simple clause" restriction, when both are simple
@ -1152,7 +1152,6 @@ static const StrategyNumber BT_refute_table[6][6] = {
* the operators are too. As of 8.0 it's possible for opfamilies to contain
* operators that are merely stable, and we dare not make deductions with
* these.)
*----------
*/
static bool
btree_predicate_proof(Expr *predicate, Node *clause, bool refute_it)
@ -1274,15 +1273,9 @@ btree_predicate_proof(Expr *predicate, Node *clause, bool refute_it)
/*
* Try to find a btree opfamily containing the needed operators.
*
* XXX this needs work!!!!!!!!!!!!!!!!!!!!!!!
*
* We must find a btree opfamily that contains both operators, else the
* implication can't be determined. Also, the pred_op has to be of
* default subtype (implying left and right input datatypes are the same);
* otherwise it's unsafe to put the pred_const on the left side of the
* test. Also, the opfamily must contain a suitable test operator matching
* the clause_const's type (which we take to mean that it has the same
* subtype as the original clause_operator).
* implication can't be determined. Also, the opfamily must contain a
* suitable test operator taking the pred_const and clause_const datatypes.
*
* If there are multiple matching opfamilies, assume we can use any one to
* determine the logical relationship of the two operators and the correct
@ -1321,12 +1314,9 @@ btree_predicate_proof(Expr *predicate, Node *clause, bool refute_it)
Form_pg_amop pred_form = (Form_pg_amop) GETSTRUCT(pred_tuple);
HeapTuple clause_tuple;
/* must be btree */
/* Must be btree */
if (pred_form->amopmethod != BTREE_AM_OID)
continue;
/* predicate operator must be default within this opfamily */
if (pred_form->amoplefttype != pred_form->amoprighttype)
continue;
/* Get the predicate operator's btree strategy number */
opfamily_id = pred_form->amopfamily;