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.

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]);
 	}
 }
 

src/backend/executor/nodeAgg.c

@@ -61,7 +61,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeAgg.c,v 1.148 2007/01/09 02:14:11 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeAgg.c,v 1.149 2007/01/10 18:06:02 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1270,16 +1270,14 @@ ExecInitAgg(Agg *node, EState *estate, int eflags)
 	if (node->numCols > 0)
 	{
 		if (node->aggstrategy == AGG_HASHED)
-			execTuplesHashPrepare(ExecGetScanType(&aggstate->ss),
-								  node->numCols,
-								  node->grpColIdx,
+			execTuplesHashPrepare(node->numCols,
+								  node->grpOperators,
 								  &aggstate->eqfunctions,
 								  &aggstate->hashfunctions);
 		else
 			aggstate->eqfunctions =
-				execTuplesMatchPrepare(ExecGetScanType(&aggstate->ss),
-									   node->numCols,
-									   node->grpColIdx);
+				execTuplesMatchPrepare(node->numCols,
+									   node->grpOperators);
 	}
 
 	/*
@@ -1519,6 +1517,13 @@ ExecInitAgg(Agg *node, EState *estate, int eflags)
 							&peraggstate->inputtypeLen,
 							&peraggstate->inputtypeByVal);
 
+			/*
+			 * Look up the sorting and comparison operators to use.  XXX it's
+			 * pretty bletcherous to be making this sort of semantic decision
+			 * in the executor.  Probably the parser should decide this and
+			 * record it in the Aggref node ... or at latest, do it in the
+			 * planner.
+			 */
 			eq_function = equality_oper_funcid(inputTypes[0]);
 			fmgr_info(eq_function, &(peraggstate->equalfn));
 			peraggstate->sortOperator = ordering_oper_opid(inputTypes[0]);

src/backend/executor/nodeGroup.c

@@ -15,7 +15,7 @@
  *	  locate group boundaries.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeGroup.c,v 1.66 2007/01/05 22:19:28 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeGroup.c,v 1.67 2007/01/10 18:06:02 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -211,9 +211,8 @@ ExecInitGroup(Group *node, EState *estate, int eflags)
 	 * Precompute fmgr lookup data for inner loop
 	 */
 	grpstate->eqfunctions =
-		execTuplesMatchPrepare(ExecGetScanType(&grpstate->ss),
-							   node->numCols,
-							   node->grpColIdx);
+		execTuplesMatchPrepare(node->numCols,
+							   node->grpOperators);
 
 	return grpstate;
 }

src/backend/executor/nodeMergejoin.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeMergejoin.c,v 1.84 2007/01/05 22:19:28 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeMergejoin.c,v 1.85 2007/01/10 18:06:02 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -156,35 +156,36 @@ typedef struct MergeJoinClauseData
  * the two expressions from the original clause.
  *
  * In addition to the expressions themselves, the planner passes the btree
- * opfamily OID and btree strategy number (BTLessStrategyNumber or
- * BTGreaterStrategyNumber) that identify the intended merge semantics for
- * each merge key.  The mergejoinable operator is an equality operator in
- * this opfamily, and the two inputs are guaranteed to be ordered in either
- * increasing or decreasing (respectively) order according to this opfamily.
- * This allows us to obtain the needed comparison functions from the opfamily.
+ * opfamily OID, btree strategy number (BTLessStrategyNumber or
+ * BTGreaterStrategyNumber), and nulls-first flag that identify the intended
+ * merge semantics for each merge key.  The mergejoinable operator is an
+ * equality operator in this opfamily, and the two inputs are guaranteed to be
+ * ordered in either increasing or decreasing (respectively) order according
+ * to this opfamily.  This allows us to obtain the needed comparison functions
+ * from the opfamily.
  */
 static MergeJoinClause
-MJExamineQuals(List *mergeclauses, List *mergefamilies, List *mergestrategies,
+MJExamineQuals(List *mergeclauses,
+			   Oid *mergefamilies,
+			   int *mergestrategies,
+			   bool *mergenullsfirst,
 			   PlanState *parent)
 {
 	MergeJoinClause clauses;
 	int			nClauses = list_length(mergeclauses);
 	int			iClause;
 	ListCell   *cl;
-	ListCell   *cf;
-	ListCell   *cs;
 
 	clauses = (MergeJoinClause) palloc0(nClauses * sizeof(MergeJoinClauseData));
 
 	iClause = 0;
-	cf = list_head(mergefamilies);
-	cs = list_head(mergestrategies);
 	foreach(cl, mergeclauses)
 	{
 		OpExpr	   *qual = (OpExpr *) lfirst(cl);
 		MergeJoinClause clause = &clauses[iClause];
-		Oid			opfamily;
-		StrategyNumber opstrategy;
+		Oid			opfamily = mergefamilies[iClause];
+		StrategyNumber opstrategy = mergestrategies[iClause];
+		bool		nulls_first = mergenullsfirst[iClause];
 		int			op_strategy;
 		Oid			op_lefttype;
 		Oid			op_righttype;
@@ -192,14 +193,10 @@ MJExamineQuals(List *mergeclauses, List *mergefamilies, List *mergestrategies,
 		RegProcedure cmpproc;
 		AclResult	aclresult;
 
-		opfamily = lfirst_oid(cf);
-		cf = lnext(cf);
-		opstrategy = lfirst_int(cs);
-		cs = lnext(cs);
-
 		/* Later we'll support both ascending and descending sort... */
 		Assert(opstrategy == BTLessStrategyNumber);
 		clause->cmpstrategy = MERGEFUNC_CMP;
+		Assert(!nulls_first);
 
 		if (!IsA(qual, OpExpr))
 			elog(ERROR, "mergejoin clause is not an OpExpr");
@@ -1525,8 +1522,9 @@ ExecInitMergeJoin(MergeJoin *node, EState *estate, int eflags)
 	 */
 	mergestate->mj_NumClauses = list_length(node->mergeclauses);
 	mergestate->mj_Clauses = MJExamineQuals(node->mergeclauses,
-											node->mergefamilies,
-											node->mergestrategies,
+											node->mergeFamilies,
+											node->mergeStrategies,
+											node->mergeNullsFirst,
 											(PlanState *) mergestate);
 
 	/*

src/backend/executor/nodeSetOp.c

@@ -21,7 +21,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeSetOp.c,v 1.23 2007/01/05 22:19:28 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeSetOp.c,v 1.24 2007/01/10 18:06:02 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -267,9 +267,8 @@ ExecInitSetOp(SetOp *node, EState *estate, int eflags)
 	 * Precompute fmgr lookup data for inner loop
 	 */
 	setopstate->eqfunctions =
-		execTuplesMatchPrepare(ExecGetResultType(&setopstate->ps),
-							   node->numCols,
-							   node->dupColIdx);
+		execTuplesMatchPrepare(node->numCols,
+							   node->dupOperators);
 
 	return setopstate;
 }

src/backend/executor/nodeUnique.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeUnique.c,v 1.54 2007/01/05 22:19:28 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeUnique.c,v 1.55 2007/01/10 18:06:02 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -159,9 +159,8 @@ ExecInitUnique(Unique *node, EState *estate, int eflags)
 	 * Precompute fmgr lookup data for inner loop
 	 */
 	uniquestate->eqfunctions =
-		execTuplesMatchPrepare(ExecGetResultType(&uniquestate->ps),
-							   node->numCols,
-							   node->uniqColIdx);
+		execTuplesMatchPrepare(node->numCols,
+							   node->uniqOperators);
 
 	return uniquestate;
 }