Modify nodeAgg.c so that no rows are returned for a GROUP BY

with no input rows, per pghackers discussions around 7/22/99.  Clean up
a bunch of ugly coding while at it; remove redundant re-lookup of
aggregate info at start of each new GROUP.  Arrange to pfree intermediate
values when they are pass-by-ref types, so that aggregates on pass-by-ref
types no longer eat memory.  This takes care of a couple of TODO items...

src/backend/executor/execQual.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/execQual.c,v 1.61 1999/09/26 02:28:15 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/execQual.c,v 1.62 1999/09/26 21:21:09 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -209,8 +209,8 @@ ExecEvalArrayRef(ArrayRef *arrayRef,
 static Datum
 ExecEvalAggref(Aggref *aggref, ExprContext *econtext, bool *isNull)
 {
-	*isNull = econtext->ecxt_nulls[aggref->aggno];
-	return econtext->ecxt_values[aggref->aggno];
+	*isNull = econtext->ecxt_aggnulls[aggref->aggno];
+	return econtext->ecxt_aggvalues[aggref->aggno];
 }
 
 /* ----------------------------------------------------------------
@@ -244,7 +244,6 @@ ExecEvalVar(Var *variable, ExprContext *econtext, bool *isNull)
 	AttrNumber	attnum;
 	HeapTuple	heapTuple;
 	TupleDesc	tuple_type;
-	Buffer		buffer;
 	bool		byval;
 	int16		len;
 
@@ -272,7 +271,6 @@ ExecEvalVar(Var *variable, ExprContext *econtext, bool *isNull)
 	 */
 	heapTuple = slot->val;
 	tuple_type = slot->ttc_tupleDescriptor;
-	buffer = slot->ttc_buffer;
 
 	attnum = variable->varattno;
 
@@ -280,14 +278,14 @@ ExecEvalVar(Var *variable, ExprContext *econtext, bool *isNull)
 	Assert(attnum <= 0 ||
 		   (attnum - 1 <= tuple_type->natts - 1 &&
 			tuple_type->attrs[attnum - 1] != NULL &&
-			variable->vartype == tuple_type->attrs[attnum - 1]->atttypid))
+			variable->vartype == tuple_type->attrs[attnum - 1]->atttypid));
 
 	/*
 	 * If the attribute number is invalid, then we are supposed to return
 	 * the entire tuple, we give back a whole slot so that callers know
 	 * what the tuple looks like.
 	 */
-		if (attnum == InvalidAttrNumber)
+	if (attnum == InvalidAttrNumber)
 	{
 		TupleTableSlot *tempSlot;
 		TupleDesc	td;
@@ -301,7 +299,7 @@ ExecEvalVar(Var *variable, ExprContext *econtext, bool *isNull)
 		tempSlot->ttc_whichplan = -1;
 
 		tup = heap_copytuple(heapTuple);
-		td = CreateTupleDescCopy(slot->ttc_tupleDescriptor);
+		td = CreateTupleDescCopy(tuple_type);
 
 		ExecSetSlotDescriptor(tempSlot, td);
 

src/backend/utils/adt/float.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/float.c,v 1.48 1999/09/21 20:58:25 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/float.c,v 1.49 1999/09/26 21:21:15 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -540,22 +540,25 @@ float4div(float32 arg1, float32 arg2)
 
 	CheckFloat4Val(val);
 	result = (float32) palloc(sizeof(float32data));
-	*result = *arg1 / *arg2;
+	*result = val;
 	return result;
 }
 
 float32
 float4inc(float32 arg1)
 {
+	float32		result;
 	double		val;
 
 	if (!arg1)
 		return (float32) NULL;
 
 	val = *arg1 + (float32data) 1.0;
+
 	CheckFloat4Val(val);
-	*arg1 = val;
-	return arg1;
+	result = (float32) palloc(sizeof(float32data));
+	*result = val;
+	return result;
 }
 
 /*
@@ -639,6 +642,7 @@ float8div(float64 arg1, float64 arg2)
 float64
 float8inc(float64 arg1)
 {
+	float64		result;
 	double		val;
 
 	if (!arg1)
@@ -646,8 +650,9 @@ float8inc(float64 arg1)
 
 	val = *arg1 + (float64data) 1.0;
 	CheckFloat8Val(val);
-	*arg1 = val;
-	return arg1;
+	result = (float64) palloc(sizeof(float64data));
+	*result = val;
+	return result;
 }
 
 
@@ -1388,7 +1393,7 @@ float48eq(float32 arg1, float64 arg2)
 	if (!arg1 || !arg2)
 		return 0;
 
-	return *arg1 == (float) *arg2;
+	return *arg1 == *arg2;
 }
 
 bool
@@ -1397,7 +1402,7 @@ float48ne(float32 arg1, float64 arg2)
 	if (!arg1 || !arg2)
 		return 0;
 
-	return *arg1 != (float) *arg2;
+	return *arg1 != *arg2;
 }
 
 bool
@@ -1406,7 +1411,7 @@ float48lt(float32 arg1, float64 arg2)
 	if (!arg1 || !arg2)
 		return 0;
 
-	return *arg1 < (float) *arg2;
+	return *arg1 < *arg2;
 }
 
 bool
@@ -1415,7 +1420,7 @@ float48le(float32 arg1, float64 arg2)
 	if (!arg1 || !arg2)
 		return 0;
 
-	return *arg1 <= (float) *arg2;
+	return *arg1 <= *arg2;
 }
 
 bool
@@ -1424,7 +1429,7 @@ float48gt(float32 arg1, float64 arg2)
 	if (!arg1 || !arg2)
 		return 0;
 
-	return *arg1 > (float) *arg2;
+	return *arg1 > *arg2;
 }
 
 bool
@@ -1433,7 +1438,7 @@ float48ge(float32 arg1, float64 arg2)
 	if (!arg1 || !arg2)
 		return 0;
 
-	return *arg1 >= (float) *arg2;
+	return *arg1 >= *arg2;
 }
 
 /*
@@ -1445,7 +1450,7 @@ float84eq(float64 arg1, float32 arg2)
 	if (!arg1 || !arg2)
 		return 0;
 
-	return (float) *arg1 == *arg2;
+	return *arg1 == *arg2;
 }
 
 bool
@@ -1454,7 +1459,7 @@ float84ne(float64 arg1, float32 arg2)
 	if (!arg1 || !arg2)
 		return 0;
 
-	return (float) *arg1 != *arg2;
+	return *arg1 != *arg2;
 }
 
 bool
@@ -1463,7 +1468,7 @@ float84lt(float64 arg1, float32 arg2)
 	if (!arg1 || !arg2)
 		return 0;
 
-	return (float) *arg1 < *arg2;
+	return *arg1 < *arg2;
 }
 
 bool
@@ -1472,7 +1477,7 @@ float84le(float64 arg1, float32 arg2)
 	if (!arg1 || !arg2)
 		return 0;
 
-	return (float) *arg1 <= *arg2;
+	return *arg1 <= *arg2;
 }
 
 bool
@@ -1481,7 +1486,7 @@ float84gt(float64 arg1, float32 arg2)
 	if (!arg1 || !arg2)
 		return 0;
 
-	return (float) *arg1 > *arg2;
+	return *arg1 > *arg2;
 }
 
 bool
@@ -1490,7 +1495,7 @@ float84ge(float64 arg1, float32 arg2)
 	if (!arg1 || !arg2)
 		return 0;
 
-	return (float) *arg1 >= *arg2;
+	return *arg1 >= *arg2;
 }
 
 /* ========== PRIVATE ROUTINES ========== */

src/include/nodes/execnodes.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: execnodes.h,v 1.35 1999/09/24 00:25:22 tgl Exp $
+ * $Id: execnodes.h,v 1.36 1999/09/26 21:21:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -88,8 +88,8 @@ typedef struct ExprContext
 	ParamListInfo ecxt_param_list_info;
 	ParamExecData *ecxt_param_exec_vals;		/* this is for subselects */
 	List	   *ecxt_range_table;
-	Datum	   *ecxt_values;	/* precomputed values for aggreg */
-	char	   *ecxt_nulls;		/* null flags for aggreg  values */
+	Datum	   *ecxt_aggvalues;	/* precomputed values for Aggref nodes */
+	bool	   *ecxt_aggnulls;	/* null flags for Aggref nodes */
 } ExprContext;
 
 /* ----------------
@@ -565,14 +565,20 @@ typedef struct MaterialState
 /* ---------------------
  *	AggregateState information
  *
- *		done			indicated whether aggregate has been materialized
+ *	Note: the associated ExprContext contains ecxt_aggvalues and ecxt_aggnulls
+ *	arrays, which hold the computed agg values for the current input group
+ *	during evaluation of an Agg node's output tuple(s).
  * -------------------------
  */
+typedef struct AggStatePerAggData *AggStatePerAgg; /* private in nodeAgg.c */
+
 typedef struct AggState
 {
 	CommonScanState csstate;	/* its first field is NodeTag */
 	List	   *aggs;			/* all Aggref nodes in targetlist & quals */
-	bool		agg_done;
+	int			numaggs;		/* length of list (could be zero!) */
+	AggStatePerAgg peragg;		/* per-Aggref working state */
+	bool		agg_done;		/* indicates completion of Agg scan */
 } AggState;
 
 /* ---------------------