Change the planner-to-executor API so that the planner tells the executor

which comparison operators to use for plan nodes involving tuple comparison
(Agg, Group, Unique, SetOp).  Formerly the executor looked up the default
equality operator for the datatype, which was really pretty shaky, since it's
possible that the data being fed to the node is sorted according to some
nondefault operator class that could have an incompatible idea of equality.
The planner knows what it has sorted by and therefore can provide the right
equality operator to use.  Also, this change moves a couple of catalog lookups
out of the executor and into the planner, which should help startup time for
pre-planned queries by some small amount.  Modify the planner to remove some
other cavalier assumptions about always being able to use the default
operators.  Also add "nulls first/last" info to the Plan node for a mergejoin
--- neither the executor nor the planner can cope yet, but at least the API is
in place.

1 files changed, 20 insertions, 29 deletions

diff --git a/src/backend/executor/execGrouping.c b/src/backend/executor/execGrouping.c
index eed92f6533f..f84c1120db2 100644
--- a/src/backend/executor/execGrouping.c
+++ b/src/backend/executor/execGrouping.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/execGrouping.c,v 1.22 2007/01/05 22:19:27 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/execGrouping.c,v 1.23 2007/01/10 18:06:02 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -183,24 +183,22 @@ execTuplesUnequal(TupleTableSlot *slot1,
  * The result is a palloc'd array.
  */
 FmgrInfo *
-execTuplesMatchPrepare(TupleDesc tupdesc,
-					   int numCols,
-					   AttrNumber *matchColIdx)
+execTuplesMatchPrepare(int numCols,
+					   Oid *eqOperators)
 {
-	FmgrInfo   *eqfunctions = (FmgrInfo *) palloc(numCols * sizeof(FmgrInfo));
+	FmgrInfo   *eqFunctions = (FmgrInfo *) palloc(numCols * sizeof(FmgrInfo));
 	int			i;
 
 	for (i = 0; i < numCols; i++)
 	{
-		AttrNumber	att = matchColIdx[i];
-		Oid			typid = tupdesc->attrs[att - 1]->atttypid;
+		Oid			eq_opr = eqOperators[i];
 		Oid			eq_function;
 
-		eq_function = equality_oper_funcid(typid);
-		fmgr_info(eq_function, &eqfunctions[i]);
+		eq_function = get_opcode(eq_opr);
+		fmgr_info(eq_function, &eqFunctions[i]);
 	}
 
-	return eqfunctions;
+	return eqFunctions;
 }
 
 /*
@@ -208,40 +206,33 @@ execTuplesMatchPrepare(TupleDesc tupdesc,
  *		Look up the equality and hashing functions needed for a TupleHashTable.
  *
  * This is similar to execTuplesMatchPrepare, but we also need to find the
- * hash functions associated with the equality operators.  *eqfunctions and
- * *hashfunctions receive the palloc'd result arrays.
+ * hash functions associated with the equality operators.  *eqFunctions and
+ * *hashFunctions receive the palloc'd result arrays.
  */
 void
-execTuplesHashPrepare(TupleDesc tupdesc,
-					  int numCols,
-					  AttrNumber *matchColIdx,
-					  FmgrInfo **eqfunctions,
-					  FmgrInfo **hashfunctions)
+execTuplesHashPrepare(int numCols,
+					  Oid *eqOperators,
+					  FmgrInfo **eqFunctions,
+					  FmgrInfo **hashFunctions)
 {
 	int			i;
 
-	*eqfunctions = (FmgrInfo *) palloc(numCols * sizeof(FmgrInfo));
-	*hashfunctions = (FmgrInfo *) palloc(numCols * sizeof(FmgrInfo));
+	*eqFunctions = (FmgrInfo *) palloc(numCols * sizeof(FmgrInfo));
+	*hashFunctions = (FmgrInfo *) palloc(numCols * sizeof(FmgrInfo));
 
 	for (i = 0; i < numCols; i++)
 	{
-		AttrNumber	att = matchColIdx[i];
-		Oid			typid = tupdesc->attrs[att - 1]->atttypid;
-		Operator	optup;
-		Oid			eq_opr;
+		Oid			eq_opr = eqOperators[i];
 		Oid			eq_function;
 		Oid			hash_function;
 
-		optup = equality_oper(typid, false);
-		eq_opr = oprid(optup);
-		eq_function = oprfuncid(optup);
-		ReleaseSysCache(optup);
+		eq_function = get_opcode(eq_opr);
 		hash_function = get_op_hash_function(eq_opr);
 		if (!OidIsValid(hash_function)) /* should not happen */
 			elog(ERROR, "could not find hash function for hash operator %u",
 				 eq_opr);
-		fmgr_info(eq_function, &(*eqfunctions)[i]);
-		fmgr_info(hash_function, &(*hashfunctions)[i]);
+		fmgr_info(eq_function, &(*eqFunctions)[i]);
+		fmgr_info(hash_function, &(*hashFunctions)[i]);
 	}
 }