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...

diff --git a/src/backend/optimizer/util/predtest.c b/src/backend/optimizer/util/predtest.c
index 5f81cae4e85d6ef8dbba3fab6a3b8f74c61e0c20..7506125dd97f94ce3f6ab6dbc8b990df83dea0f9 100644 (file)
--- a/src/backend/optimizer/util/predtest.c
+++ b/src/backend/optimizer/util/predtest.c
@@ -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;