Improving avg performance for numeric

diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 229b408..cd43416 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -259,6 +259,13 @@ typedef struct NumericVar
 	NumericDigit *digits;		/* base-NBASE digits */
 } NumericVar;
 
+/* Transition state for numeric average aggregate. */
+typedef struct AvgAggState
+{
+	Numeric 	sumX;
+	uint64 		N;
+	size_t 		sumX_size;
+} AvgAggState;
 
 /* ----------
  * Some preinitialized constants
@@ -432,7 +439,7 @@ static void trunc_var(NumericVar *var, int rscale);
 static void strip_var(NumericVar *var);
 static void compute_bucket(Numeric operand, Numeric bound1, Numeric bound2,
 			   NumericVar *count_var, NumericVar *result_var);
-
+static AvgAggState * makeAvgAggState(FunctionCallInfo fcinfo);
 
 /* ----------------------------------------------------------------------
  *
@@ -1576,6 +1583,117 @@ numeric_add(PG_FUNCTION_ARGS)
 	PG_RETURN_NUMERIC(res);
 }
 
+/*
+ * numeric_fadd() -
+ *
+ *	fast sum aggregate
+ */
+typedef struct SumAggState
+{
+	NumericVar		sumX;
+	MemoryContext		agg_context;
+	bool			isNaN;
+} SumAggState;
+
+static SumAggState *
+makeSumAggState(FunctionCallInfo fcinfo)
+{
+	SumAggState *state;
+	MemoryContext		agg_context;
+	MemoryContext		old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+	{
+		elog(ERROR, "numeric_fadd is called in non-aggregate context");
+	}
+
+	old_context = MemoryContextSwitchTo(agg_context);
+	state = palloc0(sizeof(SumAggState));
+	state->agg_context = agg_context;
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+
+Datum
+numeric_fadd_accum(PG_FUNCTION_ARGS)
+{
+	SumAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (SumAggState *) PG_GETARG_POINTER(0);
+
+	if (!PG_ARGISNULL(1))
+	{
+		bool	first = false;
+
+		if (state == NULL)
+		{
+			state = makeSumAggState(fcinfo);
+			first = true;
+		}
+
+		if (!state->isNaN)
+		{
+			Numeric par = PG_GETARG_NUMERIC(1);
+
+			if (NUMERIC_IS_NAN(par))
+			{
+				state->isNaN = true;
+			}
+			else
+			{
+				NumericVar	numvar;
+				NumericVar	tmp;
+				MemoryContext		old_context;
+
+				init_var_from_num(par, &numvar);
+
+				old_context = MemoryContextSwitchTo(state->agg_context);
+
+				if (!first)
+				{
+					memcpy(&tmp, &(state->sumX), sizeof(NumericVar));
+					init_var(&(state->sumX));
+
+					add_var(&numvar, &tmp, &(state->sumX));
+					free_var(&tmp);
+				}
+				else
+					set_var_from_var(&numvar, &(state->sumX));
+
+				MemoryContextSwitchTo(old_context);
+
+				
+			}
+		}
+	}
+
+	PG_RETURN_POINTER(state);
+}
+
+Datum
+numeric_fadd(PG_FUNCTION_ARGS)
+{
+	SumAggState *state;
+	Numeric		res;
+
+	if (PG_ARGISNULL(0))
+		PG_RETURN_NULL();
+
+	state = (SumAggState *) PG_GETARG_POINTER(0);
+	if (state->isNaN)
+	{
+		pfree(state);
+		PG_RETURN_NUMERIC(make_result(&const_nan));
+	}
+
+	res = make_result(&(state->sumX));
+	pfree(state);
+
+	PG_RETURN_NUMERIC(res);
+}
 
 /*
  * numeric_sub() -
@@ -2511,38 +2629,28 @@ do_numeric_accum(ArrayType *transarray, Numeric newval)
 	return result;
 }
 
-/*
- * Improve avg performance by not caclulating sum(X*X).
- */
-static ArrayType *
-do_numeric_avg_accum(ArrayType *transarray, Numeric newval)
+static void
+do_numeric_avg_accum(AvgAggState *state, Numeric newval)
 {
-	Datum	   *transdatums;
-	int			ndatums;
-	Datum		N,
-				sumX;
-	ArrayType  *result;
-
-	/* We assume the input is array of numeric */
-	deconstruct_array(transarray,
-					  NUMERICOID, -1, false, 'i',
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element numeric array");
-	N = transdatums[0];
-	sumX = transdatums[1];
-
-	N = DirectFunctionCall1(numeric_inc, N);
-	sumX = DirectFunctionCall2(numeric_add, sumX,
-							   NumericGetDatum(newval));
+	Numeric 	 newsumX;
+	size_t		 newsumX_size;
 
-	transdatums[0] = N;
-	transdatums[1] = sumX;
+	/* Calculate the new value for sumX. */
+	newsumX = DatumGetNumeric(DirectFunctionCall2(numeric_add, 
+							  NumericGetDatum(state->sumX),
+							  NumericGetDatum(newval)));
 
-	result = construct_array(transdatums, 2,
-							 NUMERICOID, -1, false, 'i');
+	/* Enlarge state->sumX to have enough space for the new sumX. */
+	newsumX_size = VARSIZE(newsumX);
+	if (newsumX_size > state->sumX_size)
+	{
+		state->sumX = repalloc(state->sumX, newsumX_size);
+		state->sumX_size = newsumX_size;
+	}
 
-	return result;
+	/* Update state. */
+	memcpy(state->sumX, newsumX, newsumX_size);
+	state->N++;
 }
 
 Datum
@@ -2560,10 +2668,20 @@ numeric_accum(PG_FUNCTION_ARGS)
 Datum
 numeric_avg_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Numeric		newval = PG_GETARG_NUMERIC(1);
+	AvgAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (AvgAggState *) PG_GETARG_POINTER(0);
 
-	PG_RETURN_ARRAYTYPE_P(do_numeric_avg_accum(transarray, newval));
+	if (!PG_ARGISNULL(1))
+	{
+		/* On the first time through, create the state variable. */
+		if (state == NULL)
+			state = makeAvgAggState(fcinfo);
+		
+		do_numeric_avg_accum(state, PG_GETARG_NUMERIC(1));
+	}
+
+	PG_RETURN_POINTER(state);
 }
 
 /*
@@ -2617,42 +2735,43 @@ int8_accum(PG_FUNCTION_ARGS)
 Datum
 int8_avg_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum		newval8 = PG_GETARG_DATUM(1);
-	Numeric		newval;
+	AvgAggState *state;
 
-	newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
+	state = PG_ARGISNULL(0) ? NULL : (AvgAggState *) PG_GETARG_POINTER(0);
 
-	PG_RETURN_ARRAYTYPE_P(do_numeric_avg_accum(transarray, newval));
-}
+	if (!PG_ARGISNULL(1))
+	{
+		Datum		newval8;
+		Numeric		newval;
+
+		/* On the first time through, create the state variable. */
+		if (state == NULL)
+			state = makeAvgAggState(fcinfo);
+
+		newval8 = PG_GETARG_DATUM(1);
+		newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
+		
+		do_numeric_avg_accum(state, newval);
+	}
 
+	PG_RETURN_POINTER(state);
+}
 
 Datum
 numeric_avg(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Numeric		N,
-				sumX;
-
-	/* We assume the input is array of numeric */
-	deconstruct_array(transarray,
-					  NUMERICOID, -1, false, 'i',
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element numeric array");
-	N = DatumGetNumeric(transdatums[0]);
-	sumX = DatumGetNumeric(transdatums[1]);
+	Datum 		 countd;
+	AvgAggState *state;
 
-	/* SQL92 defines AVG of no values to be NULL */
-	/* N is zero iff no digits (cf. numeric_uminus) */
-	if (NUMERIC_NDIGITS(N) == 0)
+	if (PG_ARGISNULL(0))
 		PG_RETURN_NULL();
 
+	state = (AvgAggState *) PG_GETARG_POINTER(0);
+	countd = DirectFunctionCall1(int8_numeric, Int64GetDatum(state->N));
+
 	PG_RETURN_DATUM(DirectFunctionCall2(numeric_div,
-										NumericGetDatum(sumX),
-										NumericGetDatum(N)));
+										NumericGetDatum(state->sumX),
+										countd));
 }
 
 /*
@@ -6170,3 +6289,39 @@ strip_var(NumericVar *var)
 	var->digits = digits;
 	var->ndigits = ndigits;
 }
+
+/*
+ * makeAvgAggState
+ *
+ * Initialize state for numeric avg aggregate in the aggregate context
+ */
+static AvgAggState * 
+makeAvgAggState(FunctionCallInfo fcinfo)
+{
+	AvgAggState 	*state;
+	NumericVar 		*sumX_var;
+	MemoryContext 	 agg_context;
+	MemoryContext 	 old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+	{
+		/* cannot be called directly because of internal-type argument */
+		elog(ERROR, "numeric_avg_accum called in non-aggregate context");
+	}
+
+	sumX_var = palloc0(sizeof(NumericVar));
+	zero_var(sumX_var);
+
+	/*
+	 * Create state in aggregate context.  It'll stay there across subsequent
+	 * calls.
+	 */
+	old_context = MemoryContextSwitchTo(agg_context);
+	state = palloc0(sizeof(AvgAggState));
+	state->sumX = make_result(sumX_var);
+	state->sumX_size = VARSIZE(state->sumX);
+	state->N = 0;
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
diff --git a/src/include/catalog/pg_aggregate.h b/src/include/catalog/pg_aggregate.h
index 6fb10a9..fb12637 100644
--- a/src/include/catalog/pg_aggregate.h
+++ b/src/include/catalog/pg_aggregate.h
@@ -77,13 +77,14 @@ typedef FormData_pg_aggregate *Form_pg_aggregate;
  */
 
 /* avg */
-DATA(insert ( 2100	int8_avg_accum	numeric_avg		0	1231	"{0,0}" ));
+DATA(insert ( 2100	int8_avg_accum	numeric_avg		0	2281	_null_ ));
 DATA(insert ( 2101	int4_avg_accum	int8_avg		0	1016	"{0,0}" ));
 DATA(insert ( 2102	int2_avg_accum	int8_avg		0	1016	"{0,0}" ));
-DATA(insert ( 2103	numeric_avg_accum	numeric_avg		0	1231	"{0,0}" ));
+DATA(insert ( 2103	numeric_avg_accum	numeric_avg		0	2281	_null_ ));
 DATA(insert ( 2104	float4_accum	float8_avg		0	1022	"{0,0,0}" ));
 DATA(insert ( 2105	float8_accum	float8_avg		0	1022	"{0,0,0}" ));
 DATA(insert ( 2106	interval_accum	interval_avg	0	1187	"{0 second,0 second}" ));
+DATA(insert ( 3179	numeric_fadd_accum	numeric_fadd		0	2281	_null_ ));
 
 /* sum */
 DATA(insert ( 2107	int8_sum		-				0	1700	_null_ ));
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index c97056e..94e5d4e 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2385,18 +2385,22 @@ DATA(insert OID = 1832 (  float8_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f t f
 DESCR("aggregate final function");
 DATA(insert OID = 1833 (  numeric_accum    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 1700" _null_ _null_ _null_ _null_ numeric_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 2858 (  numeric_avg_accum    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 1700" _null_ _null_ _null_ _null_ numeric_avg_accum _null_ _null_ _null_ ));
+DATA(insert OID = 2858 (  numeric_avg_accum    PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 1700" _null_ _null_ _null_ _null_ numeric_avg_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
+DATA(insert OID = 3177 (  numeric_fadd_accum    PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 1700" _null_ _null_ _null_ _null_ numeric_fadd_accum _null_ _null_ _null_ ));
+DESCR("fast sum aggregate transition function");
 DATA(insert OID = 1834 (  int2_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 21" _null_ _null_ _null_ _null_ int2_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
 DATA(insert OID = 1835 (  int4_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 23" _null_ _null_ _null_ _null_ int4_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
 DATA(insert OID = 1836 (  int8_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 20" _null_ _null_ _null_ _null_ int8_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 2746 (  int8_avg_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 20" _null_ _null_ _null_ _null_ int8_avg_accum _null_ _null_ _null_ ));
+DATA(insert OID = 2746 (  int8_avg_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 20" _null_ _null_ _null_ _null_ int8_avg_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 1837 (  numeric_avg	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_avg _null_ _null_ _null_ ));
+DATA(insert OID = 1837 (  numeric_avg	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_avg _null_ _null_ _null_ ));
 DESCR("aggregate final function");
+DATA(insert OID = 3188 (  numeric_fadd	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_fadd _null_ _null_ _null_ ));
+DESCR("aggregate fast sum final function");
 DATA(insert OID = 2514 (  numeric_var_pop  PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_var_pop _null_ _null_ _null_ ));
 DESCR("aggregate final function");
 DATA(insert OID = 1838 (  numeric_var_samp PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_var_samp _null_ _null_ _null_ ));
@@ -3034,7 +3038,8 @@ DATA(insert OID = 2105 (  avg				PGNSP PGUID 12 1 0 0 0 t f f f f f i 1 0 701 "7
 DESCR("the average (arithmetic mean) as float8 of all float8 values");
 DATA(insert OID = 2106 (  avg				PGNSP PGUID 12 1 0 0 0 t f f f f f i 1 0 1186 "1186" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
 DESCR("the average (arithmetic mean) as interval of all interval values");
-
+DATA(insert OID = 3179 (  fsum				PGNSP PGUID 12 1 0 0 0 t f f f f f i 1 0 1700 "1700" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+DESCR("the sum as numeric of all numeric values");
 DATA(insert OID = 2107 (  sum				PGNSP PGUID 12 1 0 0 0 t f f f f f i 1 0 1700 "20" _null_ _null_ _null_ _null_	aggregate_dummy _null_ _null_ _null_ ));
 DESCR("sum as numeric across all bigint input values");
 DATA(insert OID = 2108 (  sum				PGNSP PGUID 12 1 0 0 0 t f f f f f i 1 0 20 "23" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index c0debe4..d680367 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -949,6 +949,8 @@ extern Datum numeric_lt(PG_FUNCTION_ARGS);
 extern Datum numeric_le(PG_FUNCTION_ARGS);
 extern Datum numeric_add(PG_FUNCTION_ARGS);
 extern Datum numeric_sub(PG_FUNCTION_ARGS);
+extern Datum numeric_fadd_accum(PG_FUNCTION_ARGS);
+extern Datum numeric_fadd(PG_FUNCTION_ARGS);
 extern Datum numeric_mul(PG_FUNCTION_ARGS);
 extern Datum numeric_div(PG_FUNCTION_ARGS);
 extern Datum numeric_div_trunc(PG_FUNCTION_ARGS);

diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 229b408..e8294b6 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -2464,94 +2464,122 @@ numeric_float4(PG_FUNCTION_ARGS)
  *
  * Aggregate functions
  *
- * The transition datatype for all these aggregates is a 3-element array
- * of Numeric, holding the values N, sum(X), sum(X*X) in that order.
- *
- * We represent N as a numeric mainly to avoid having to build a special
- * datatype; it's unlikely it'd overflow an int4, but ...
+ * The transition datatype for all these aggregates is a pointer to 
+ * a struct NumericAggState allocated in the aggregate context.
  *
  * ----------------------------------------------------------------------
  */
 
-static ArrayType *
-do_numeric_accum(ArrayType *transarray, Numeric newval)
+typedef struct NumericAggState
+{
+	bool 			first;
+	bool 			isNaN;
+	uint64			N;
+	NumericVar 		sumX;
+	NumericVar 		sumX2;
+	bool 			calcSumX2;
+	MemoryContext 	agg_context;
+} NumericAggState;
+
+static NumericAggState *
+makeNumericAggState(FunctionCallInfo fcinfo, bool calcSumX2)
 {
-	Datum	   *transdatums;
-	int			ndatums;
-	Datum		N,
-				sumX,
-				sumX2;
-	ArrayType  *result;
-
-	/* We assume the input is array of numeric */
-	deconstruct_array(transarray,
-					  NUMERICOID, -1, false, 'i',
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 3)
-		elog(ERROR, "expected 3-element numeric array");
-	N = transdatums[0];
-	sumX = transdatums[1];
-	sumX2 = transdatums[2];
-
-	N = DirectFunctionCall1(numeric_inc, N);
-	sumX = DirectFunctionCall2(numeric_add, sumX,
-							   NumericGetDatum(newval));
-	sumX2 = DirectFunctionCall2(numeric_add, sumX2,
-								DirectFunctionCall2(numeric_mul,
-													NumericGetDatum(newval),
-													NumericGetDatum(newval)));
-
-	transdatums[0] = N;
-	transdatums[1] = sumX;
-	transdatums[2] = sumX2;
-
-	result = construct_array(transdatums, 3,
-							 NUMERICOID, -1, false, 'i');
+	NumericAggState 	*state;
+	MemoryContext 		 agg_context;
+	MemoryContext 		 old_context;
 
-	return result;
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+	{
+		elog(ERROR, "this is called in non-aggregate context");
+	}
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = palloc0(sizeof(NumericAggState));
+	state->first = true;
+	state->calcSumX2 = calcSumX2;
+	state->agg_context = agg_context;
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
 }
 
-/*
- * Improve avg performance by not caclulating sum(X*X).
- */
-static ArrayType *
-do_numeric_avg_accum(ArrayType *transarray, Numeric newval)
+static void
+do_numeric_accum(NumericAggState *state, Numeric newval)
 {
-	Datum	   *transdatums;
-	int			ndatums;
-	Datum		N,
-				sumX;
-	ArrayType  *result;
-
-	/* We assume the input is array of numeric */
-	deconstruct_array(transarray,
-					  NUMERICOID, -1, false, 'i',
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element numeric array");
-	N = transdatums[0];
-	sumX = transdatums[1];
-
-	N = DirectFunctionCall1(numeric_inc, N);
-	sumX = DirectFunctionCall2(numeric_add, sumX,
-							   NumericGetDatum(newval));
-
-	transdatums[0] = N;
-	transdatums[1] = sumX;
-
-	result = construct_array(transdatums, 2,
-							 NUMERICOID, -1, false, 'i');
+	NumericVar 		X;
+	NumericVar 		X2;
+	MemoryContext 	old_context;
+	bool 			first;
+	
+	first = state->first;
+	state->first = false;
+	state->N++;
+
+	if (state->isNaN || NUMERIC_IS_NAN(newval))
+	{
+		state->isNaN = true;
+		return;
+	}
 
-	return result;
+	init_var_from_num(newval, &X);
+
+	if (state->calcSumX2)
+	{
+		init_var(&X2);
+		mul_var(&X, &X, &X2, X.dscale * 2);
+	}
+
+	old_context = MemoryContextSwitchTo(state->agg_context);
+
+	if (!first)
+	{
+		NumericVar preSumX;
+
+		memcpy(&preSumX, &(state->sumX), sizeof(NumericVar));
+		init_var(&(state->sumX));
+		add_var(&X, &preSumX, &(state->sumX));
+		free_var(&preSumX);
+
+		if (state->calcSumX2)
+		{
+			NumericVar preSumX2;
+
+			memcpy(&preSumX2, &(state->sumX2), sizeof(NumericVar));
+			init_var(&(state->sumX2));
+			add_var(&X2, &preSumX2, &(state->sumX2));
+			free_var(&preSumX2);
+		}
+	}
+	else
+	{
+		set_var_from_var(&X, &(state->sumX));
+
+		if (state->calcSumX2)
+			set_var_from_var(&X2, &(state->sumX2));
+	}
+
+	MemoryContextSwitchTo(old_context);
 }
 
 Datum
 numeric_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Numeric		newval = PG_GETARG_NUMERIC(1);
+	NumericAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+	if (!PG_ARGISNULL(1))
+	{
+		/* On the first time through, create the state variable. */
+		if (state == NULL)
+			state = makeNumericAggState(fcinfo, true);
+		
+		do_numeric_accum(state, PG_GETARG_NUMERIC(1));
+	}
 
-	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
+	PG_RETURN_POINTER(state);
 }
 
 /*
@@ -2560,10 +2588,20 @@ numeric_accum(PG_FUNCTION_ARGS)
 Datum
 numeric_avg_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Numeric		newval = PG_GETARG_NUMERIC(1);
+	NumericAggState *state;
 
-	PG_RETURN_ARRAYTYPE_P(do_numeric_avg_accum(transarray, newval));
+	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+	if (!PG_ARGISNULL(1))
+	{
+		/* On the first time through, create the state variable. */
+		if (state == NULL)
+			state = makeNumericAggState(fcinfo, false);
+		
+		do_numeric_accum(state, PG_GETARG_NUMERIC(1));
+	}
+
+	PG_RETURN_POINTER(state);
 }
 
 /*
@@ -2578,37 +2616,70 @@ numeric_avg_accum(PG_FUNCTION_ARGS)
 Datum
 int2_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum		newval2 = PG_GETARG_DATUM(1);
-	Numeric		newval;
+	NumericAggState *state;
 
-	newval = DatumGetNumeric(DirectFunctionCall1(int2_numeric, newval2));
+	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+	if (!PG_ARGISNULL(1))
+	{
+		Datum		newval2 = PG_GETARG_DATUM(1);
+		Numeric		newval;
+
+		/* On the first time through, create the state variable. */
+		if (state == NULL)
+			state = makeNumericAggState(fcinfo, true);
+		
+		newval = DatumGetNumeric(DirectFunctionCall1(int2_numeric, newval2));
+		do_numeric_accum(state, newval);
+	}
 
-	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
+	PG_RETURN_POINTER(state);
 }
 
 Datum
 int4_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum		newval4 = PG_GETARG_DATUM(1);
-	Numeric		newval;
+	NumericAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
 
-	newval = DatumGetNumeric(DirectFunctionCall1(int4_numeric, newval4));
+	if (!PG_ARGISNULL(1))
+	{
+		Datum		newval4 = PG_GETARG_DATUM(1);
+		Numeric		newval;
+
+		/* On the first time through, create the state variable. */
+		if (state == NULL)
+			state = makeNumericAggState(fcinfo, true);
+		
+		newval = DatumGetNumeric(DirectFunctionCall1(int4_numeric, newval4));
+		do_numeric_accum(state, newval);
+	}
 
-	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
+	PG_RETURN_POINTER(state);
 }
 
 Datum
 int8_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum		newval8 = PG_GETARG_DATUM(1);
-	Numeric		newval;
+	NumericAggState *state;
 
-	newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
+	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
 
-	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
+	if (!PG_ARGISNULL(1))
+	{
+		Datum		newval8 = PG_GETARG_DATUM(1);
+		Numeric		newval;
+
+		/* On the first time through, create the state variable. */
+		if (state == NULL)
+			state = makeNumericAggState(fcinfo, true);
+		
+		newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
+		do_numeric_accum(state, newval);
+	}
+
+	PG_RETURN_POINTER(state);
 }
 
 /*
@@ -2617,48 +2688,61 @@ int8_accum(PG_FUNCTION_ARGS)
 Datum
 int8_avg_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum		newval8 = PG_GETARG_DATUM(1);
-	Numeric		newval;
+	NumericAggState *state;
 
-	newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
+	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
 
-	PG_RETURN_ARRAYTYPE_P(do_numeric_avg_accum(transarray, newval));
-}
+	if (!PG_ARGISNULL(1))
+	{
+		Datum		newval8 = PG_GETARG_DATUM(1);
+		Numeric		newval;
+
+		/* On the first time through, create the state variable. */
+		if (state == NULL)
+			state = makeNumericAggState(fcinfo, false);
+		
+		newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
+		do_numeric_accum(state, newval);
+	}
 
+	PG_RETURN_POINTER(state);
+}
 
 Datum
 numeric_avg(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Numeric		N,
-				sumX;
-
-	/* We assume the input is array of numeric */
-	deconstruct_array(transarray,
-					  NUMERICOID, -1, false, 'i',
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element numeric array");
-	N = DatumGetNumeric(transdatums[0]);
-	sumX = DatumGetNumeric(transdatums[1]);
+	Datum 		 		N_datum;
+	Datum 				sumX_datum;
+	NumericAggState 	*state;
 
-	/* SQL92 defines AVG of no values to be NULL */
-	/* N is zero iff no digits (cf. numeric_uminus) */
-	if (NUMERIC_NDIGITS(N) == 0)
+	if (PG_ARGISNULL(0))
+		PG_RETURN_NULL();
+
+	state = (NumericAggState *) PG_GETARG_POINTER(0);
+
+	N_datum = DirectFunctionCall1(int8_numeric, Int64GetDatum(state->N));
+	sumX_datum = NumericGetDatum(make_result(&state->sumX));
+
+	PG_RETURN_DATUM(DirectFunctionCall2(numeric_div, sumX_datum, N_datum));
+}
+
+Datum
+numeric_sum(PG_FUNCTION_ARGS)
+{
+	NumericAggState 	*state;
+
+	if (PG_ARGISNULL(0))
 		PG_RETURN_NULL();
 
-	PG_RETURN_DATUM(DirectFunctionCall2(numeric_div,
-										NumericGetDatum(sumX),
-										NumericGetDatum(N)));
+	state = (NumericAggState *) PG_GETARG_POINTER(0);
+
+	PG_RETURN_NUMERIC(make_result(&(state->sumX)));
 }
 
 /*
  * Workhorse routine for the standard deviance and variance
- * aggregates. 'transarray' is the aggregate's transition
- * array. 'variance' specifies whether we should calculate the
+ * aggregates. 'state' is aggregate's transition state.
+ * 'variance' specifies whether we should calculate the
  * variance or the standard deviation. 'sample' indicates whether the
  * caller is interested in the sample or the population
  * variance/stddev.
@@ -2667,16 +2751,11 @@ numeric_avg(PG_FUNCTION_ARGS)
  * *is_null is set to true and NULL is returned.
  */
 static Numeric
-numeric_stddev_internal(ArrayType *transarray,
+numeric_stddev_internal(NumericAggState *state,
 						bool variance, bool sample,
 						bool *is_null)
 {
-	Datum	   *transdatums;
-	int			ndatums;
-	Numeric		N,
-				sumX,
-				sumX2,
-				res;
+	Numeric		res;
 	NumericVar	vN,
 				vsumX,
 				vsumX2,
@@ -2684,22 +2763,24 @@ numeric_stddev_internal(ArrayType *transarray,
 	NumericVar *comp;
 	int			rscale;
 
+	if (state == NULL)
+	{
+		*is_null = true;
+		return NULL;
+	}
+
 	*is_null = false;
 
-	/* We assume the input is array of numeric */
-	deconstruct_array(transarray,
-					  NUMERICOID, -1, false, 'i',
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 3)
-		elog(ERROR, "expected 3-element numeric array");
-	N = DatumGetNumeric(transdatums[0]);
-	sumX = DatumGetNumeric(transdatums[1]);
-	sumX2 = DatumGetNumeric(transdatums[2]);
-
-	if (NUMERIC_IS_NAN(N) || NUMERIC_IS_NAN(sumX) || NUMERIC_IS_NAN(sumX2))
+	if (state->isNaN)
 		return make_result(&const_nan);
 
-	init_var_from_num(N, &vN);
+	init_var(&vN);
+	init_var(&vsumX);
+	init_var(&vsumX2);
+
+	int8_to_numericvar(state->N, &vN);
+	set_var_from_var(&(state->sumX), &vsumX);
+	set_var_from_var(&(state->sumX2), &vsumX2);
 
 	/*
 	 * Sample stddev and variance are undefined when N <= 1; population stddev
@@ -2719,8 +2800,8 @@ numeric_stddev_internal(ArrayType *transarray,
 	init_var(&vNminus1);
 	sub_var(&vN, &const_one, &vNminus1);
 
-	init_var_from_num(sumX, &vsumX);
-	init_var_from_num(sumX2, &vsumX2);
+	set_var_from_var(&(state->sumX), &vsumX);
+	set_var_from_var(&(state->sumX2), &vsumX2);
 
 	/* compute rscale for mul_var calls */
 	rscale = vsumX.dscale * 2;
@@ -2761,7 +2842,7 @@ numeric_var_samp(PG_FUNCTION_ARGS)
 	Numeric		res;
 	bool		is_null;
 
-	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
+	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
 								  true, true, &is_null);
 
 	if (is_null)
@@ -2776,7 +2857,7 @@ numeric_stddev_samp(PG_FUNCTION_ARGS)
 	Numeric		res;
 	bool		is_null;
 
-	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
+	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
 								  false, true, &is_null);
 
 	if (is_null)
@@ -2791,7 +2872,7 @@ numeric_var_pop(PG_FUNCTION_ARGS)
 	Numeric		res;
 	bool		is_null;
 
-	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
+	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
 								  true, false, &is_null);
 
 	if (is_null)
@@ -2806,7 +2887,7 @@ numeric_stddev_pop(PG_FUNCTION_ARGS)
 	Numeric		res;
 	bool		is_null;
 
-	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
+	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
 								  false, false, &is_null);
 
 	if (is_null)
diff --git a/src/include/catalog/pg_aggregate.h b/src/include/catalog/pg_aggregate.h
index 6fb10a9..6f4090e 100644
--- a/src/include/catalog/pg_aggregate.h
+++ b/src/include/catalog/pg_aggregate.h
@@ -77,23 +77,23 @@ typedef FormData_pg_aggregate *Form_pg_aggregate;
  */
 
 /* avg */
-DATA(insert ( 2100	int8_avg_accum	numeric_avg		0	1231	"{0,0}" ));
+DATA(insert ( 2100	int8_avg_accum	numeric_avg		0	2281	_null_ ));
 DATA(insert ( 2101	int4_avg_accum	int8_avg		0	1016	"{0,0}" ));
 DATA(insert ( 2102	int2_avg_accum	int8_avg		0	1016	"{0,0}" ));
-DATA(insert ( 2103	numeric_avg_accum	numeric_avg		0	1231	"{0,0}" ));
+DATA(insert ( 2103	numeric_avg_accum	numeric_avg		0	2281	_null_ ));
 DATA(insert ( 2104	float4_accum	float8_avg		0	1022	"{0,0,0}" ));
 DATA(insert ( 2105	float8_accum	float8_avg		0	1022	"{0,0,0}" ));
 DATA(insert ( 2106	interval_accum	interval_avg	0	1187	"{0 second,0 second}" ));
 
 /* sum */
-DATA(insert ( 2107	int8_sum		-				0	1700	_null_ ));
+DATA(insert ( 2107	int8_avg_accum	numeric_sum		0	2281	_null_ ));
 DATA(insert ( 2108	int4_sum		-				0	20		_null_ ));
 DATA(insert ( 2109	int2_sum		-				0	20		_null_ ));
 DATA(insert ( 2110	float4pl		-				0	700		_null_ ));
 DATA(insert ( 2111	float8pl		-				0	701		_null_ ));
 DATA(insert ( 2112	cash_pl			-				0	790		_null_ ));
 DATA(insert ( 2113	interval_pl		-				0	1186	_null_ ));
-DATA(insert ( 2114	numeric_add		-				0	1700	_null_ ));
+DATA(insert ( 2114	numeric_avg_accum	numeric_sum	0	2281	_null_ ));
 
 /* max */
 DATA(insert ( 2115	int8larger		-				413		20		_null_ ));
@@ -144,52 +144,52 @@ DATA(insert ( 2147	int8inc_any		-				0		20		"0" ));
 DATA(insert ( 2803	int8inc			-				0		20		"0" ));
 
 /* var_pop */
-DATA(insert ( 2718	int8_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
-DATA(insert ( 2719	int4_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
-DATA(insert ( 2720	int2_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
+DATA(insert ( 2718	int8_accum	numeric_var_pop 0	2281	_null_ ));
+DATA(insert ( 2719	int4_accum	numeric_var_pop 0	2281	_null_ ));
+DATA(insert ( 2720	int2_accum	numeric_var_pop 0	2281	_null_ ));
 DATA(insert ( 2721	float4_accum	float8_var_pop 0	1022	"{0,0,0}" ));
 DATA(insert ( 2722	float8_accum	float8_var_pop 0	1022	"{0,0,0}" ));
-DATA(insert ( 2723	numeric_accum  numeric_var_pop 0	1231	"{0,0,0}" ));
+DATA(insert ( 2723	numeric_accum  numeric_var_pop 0	2281	_null_ ));
 
 /* var_samp */
-DATA(insert ( 2641	int8_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2642	int4_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2643	int2_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
+DATA(insert ( 2641	int8_accum	numeric_var_samp	0	2281	_null_ ));
+DATA(insert ( 2642	int4_accum	numeric_var_samp	0	2281	_null_ ));
+DATA(insert ( 2643	int2_accum	numeric_var_samp	0	2281	_null_ ));
 DATA(insert ( 2644	float4_accum	float8_var_samp 0	1022	"{0,0,0}" ));
 DATA(insert ( 2645	float8_accum	float8_var_samp 0	1022	"{0,0,0}" ));
-DATA(insert ( 2646	numeric_accum  numeric_var_samp 0	1231	"{0,0,0}" ));
+DATA(insert ( 2646	numeric_accum  numeric_var_samp 0	2281	_null_ ));
 
 /* variance: historical Postgres syntax for var_samp */
-DATA(insert ( 2148	int8_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2149	int4_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2150	int2_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
+DATA(insert ( 2148	int8_accum	numeric_var_samp	0	2281	_null_ ));
+DATA(insert ( 2149	int4_accum	numeric_var_samp	0	2281	_null_ ));
+DATA(insert ( 2150	int2_accum	numeric_var_samp	0	2281	_null_ ));
 DATA(insert ( 2151	float4_accum	float8_var_samp 0	1022	"{0,0,0}" ));
 DATA(insert ( 2152	float8_accum	float8_var_samp 0	1022	"{0,0,0}" ));
-DATA(insert ( 2153	numeric_accum  numeric_var_samp 0	1231	"{0,0,0}" ));
+DATA(insert ( 2153	numeric_accum  numeric_var_samp 0	2281	_null_ ));
 
 /* stddev_pop */
-DATA(insert ( 2724	int8_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
-DATA(insert ( 2725	int4_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
-DATA(insert ( 2726	int2_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
+DATA(insert ( 2724	int8_accum	numeric_stddev_pop		0	2281	_null_ ));
+DATA(insert ( 2725	int4_accum	numeric_stddev_pop		0	2281	_null_ ));
+DATA(insert ( 2726	int2_accum	numeric_stddev_pop		0	2281	_null_ ));
 DATA(insert ( 2727	float4_accum	float8_stddev_pop	0	1022	"{0,0,0}" ));
 DATA(insert ( 2728	float8_accum	float8_stddev_pop	0	1022	"{0,0,0}" ));
-DATA(insert ( 2729	numeric_accum	numeric_stddev_pop	0	1231	"{0,0,0}" ));
+DATA(insert ( 2729	numeric_accum	numeric_stddev_pop	0	2281	_null_ ));
 
 /* stddev_samp */
-DATA(insert ( 2712	int8_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2713	int4_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2714	int2_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
+DATA(insert ( 2712	int8_accum	numeric_stddev_samp		0	2281	_null_ ));
+DATA(insert ( 2713	int4_accum	numeric_stddev_samp		0	2281	_null_ ));
+DATA(insert ( 2714	int2_accum	numeric_stddev_samp		0	2281	_null_ ));
 DATA(insert ( 2715	float4_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
 DATA(insert ( 2716	float8_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
-DATA(insert ( 2717	numeric_accum	numeric_stddev_samp 0	1231	"{0,0,0}" ));
+DATA(insert ( 2717	numeric_accum	numeric_stddev_samp 0	2281	_null_ ));
 
 /* stddev: historical Postgres syntax for stddev_samp */
-DATA(insert ( 2154	int8_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2155	int4_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2156	int2_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
+DATA(insert ( 2154	int8_accum	numeric_stddev_samp		0	2281	_null_ ));
+DATA(insert ( 2155	int4_accum	numeric_stddev_samp		0	2281	_null_ ));
+DATA(insert ( 2156	int2_accum	numeric_stddev_samp		0	2281	_null_ ));
 DATA(insert ( 2157	float4_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
 DATA(insert ( 2158	float8_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
-DATA(insert ( 2159	numeric_accum	numeric_stddev_samp 0	1231	"{0,0,0}" ));
+DATA(insert ( 2159	numeric_accum	numeric_stddev_samp 0	2281	_null_ ));
 
 /* SQL2003 binary regression aggregates */
 DATA(insert ( 2818	int8inc_float8_float8		-				0	20		"0" ));
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index c97056e..8541112 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2383,27 +2383,29 @@ DATA(insert OID = 2513 (  float8_stddev_pop PGNSP PGUID 12 1 0 0 0 f f f f t f i
 DESCR("aggregate final function");
 DATA(insert OID = 1832 (  float8_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 701 "1022" _null_ _null_ _null_ _null_ float8_stddev_samp _null_ _null_ _null_ ));
 DESCR("aggregate final function");
-DATA(insert OID = 1833 (  numeric_accum    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 1700" _null_ _null_ _null_ _null_ numeric_accum _null_ _null_ _null_ ));
+DATA(insert OID = 1833 (  numeric_accum    PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 1700" _null_ _null_ _null_ _null_ numeric_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 2858 (  numeric_avg_accum    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 1700" _null_ _null_ _null_ _null_ numeric_avg_accum _null_ _null_ _null_ ));
+DATA(insert OID = 2858 (  numeric_avg_accum    PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 1700" _null_ _null_ _null_ _null_ numeric_avg_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 1834 (  int2_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 21" _null_ _null_ _null_ _null_ int2_accum _null_ _null_ _null_ ));
+DATA(insert OID = 1834 (  int2_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 21" _null_ _null_ _null_ _null_ int2_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 1835 (  int4_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 23" _null_ _null_ _null_ _null_ int4_accum _null_ _null_ _null_ ));
+DATA(insert OID = 1835 (  int4_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 23" _null_ _null_ _null_ _null_ int4_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 1836 (  int8_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 20" _null_ _null_ _null_ _null_ int8_accum _null_ _null_ _null_ ));
+DATA(insert OID = 1836 (  int8_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 20" _null_ _null_ _null_ _null_ int8_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 2746 (  int8_avg_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 20" _null_ _null_ _null_ _null_ int8_avg_accum _null_ _null_ _null_ ));
+DATA(insert OID = 2746 (  int8_avg_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 20" _null_ _null_ _null_ _null_ int8_avg_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 1837 (  numeric_avg	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_avg _null_ _null_ _null_ ));
+DATA(insert OID = 1837 (  numeric_avg	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_avg _null_ _null_ _null_ ));
 DESCR("aggregate final function");
-DATA(insert OID = 2514 (  numeric_var_pop  PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_var_pop _null_ _null_ _null_ ));
+DATA(insert OID = 3179 (  numeric_sum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_sum _null_ _null_ _null_ ));
 DESCR("aggregate final function");
-DATA(insert OID = 1838 (  numeric_var_samp PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_var_samp _null_ _null_ _null_ ));
+DATA(insert OID = 2514 (  numeric_var_pop  PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_var_pop _null_ _null_ _null_ ));
 DESCR("aggregate final function");
-DATA(insert OID = 2596 (  numeric_stddev_pop PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_	numeric_stddev_pop _null_ _null_ _null_ ));
+DATA(insert OID = 1838 (  numeric_var_samp PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_var_samp _null_ _null_ _null_ ));
 DESCR("aggregate final function");
-DATA(insert OID = 1839 (  numeric_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_stddev_samp _null_ _null_ _null_ ));
+DATA(insert OID = 2596 (  numeric_stddev_pop PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_	numeric_stddev_pop _null_ _null_ _null_ ));
+DESCR("aggregate final function");
+DATA(insert OID = 1839 (  numeric_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_stddev_samp _null_ _null_ _null_ ));
 DESCR("aggregate final function");
 DATA(insert OID = 1840 (  int2_sum		   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 20 "20 21" _null_ _null_ _null_ _null_ int2_sum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index c0debe4..fb8880f 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -980,6 +980,7 @@ extern Datum int4_accum(PG_FUNCTION_ARGS);
 extern Datum int8_accum(PG_FUNCTION_ARGS);
 extern Datum int8_avg_accum(PG_FUNCTION_ARGS);
 extern Datum numeric_avg(PG_FUNCTION_ARGS);
+extern Datum numeric_sum(PG_FUNCTION_ARGS);
 extern Datum numeric_var_pop(PG_FUNCTION_ARGS);
 extern Datum numeric_var_samp(PG_FUNCTION_ARGS);
 extern Datum numeric_stddev_pop(PG_FUNCTION_ARGS);

diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 6c0ef5b..4b752d6 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -373,6 +373,12 @@
       <entry>Data type of the aggregate function's internal transition (state) data</entry>
      </row>
      <row>
+      <entry><structfield>aggtransspace</structfield></entry>
+      <entry><type>int4</type></entry>
+      <entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
+      <entry>Approximation for the average size of the aggregate function's internal transition (state) data</entry>
+     </row>
+     <row>
       <entry><structfield>agginitval</structfield></entry>
       <entry><type>text</type></entry>
       <entry></entry>
diff --git a/doc/src/sgml/ref/create_aggregate.sgml b/doc/src/sgml/ref/create_aggregate.sgml
index d5e4e27..594d095 100644
--- a/doc/src/sgml/ref/create_aggregate.sgml
+++ b/doc/src/sgml/ref/create_aggregate.sgml
@@ -24,6 +24,7 @@ PostgreSQL documentation
 CREATE AGGREGATE <replaceable class="PARAMETER">name</replaceable> ( <replaceable class="PARAMETER">input_data_type</replaceable> [ , ... ] ) (
     SFUNC = <replaceable class="PARAMETER">sfunc</replaceable>,
     STYPE = <replaceable class="PARAMETER">state_data_type</replaceable>
+    [ , SSPACE = <replaceable class="PARAMETER">state_data_size</replaceable> ]
     [ , FINALFUNC = <replaceable class="PARAMETER">ffunc</replaceable> ]
     [ , INITCOND = <replaceable class="PARAMETER">initial_condition</replaceable> ]
     [ , SORTOP = <replaceable class="PARAMETER">sort_operator</replaceable> ]
@@ -35,6 +36,7 @@ CREATE AGGREGATE <replaceable class="PARAMETER">name</replaceable> (
     BASETYPE = <replaceable class="PARAMETER">base_type</replaceable>,
     SFUNC = <replaceable class="PARAMETER">sfunc</replaceable>,
     STYPE = <replaceable class="PARAMETER">state_data_type</replaceable>
+    [ , SSPACE = <replaceable class="PARAMETER">state_data_size</replaceable> ]
     [ , FINALFUNC = <replaceable class="PARAMETER">ffunc</replaceable> ]
     [ , INITCOND = <replaceable class="PARAMETER">initial_condition</replaceable> ]
     [ , SORTOP = <replaceable class="PARAMETER">sort_operator</replaceable> ]
@@ -241,6 +243,18 @@ SELECT col FROM tab ORDER BY col USING sortop LIMIT 1;
    </varlistentry>
 
    <varlistentry>
+    <term><replaceable class="PARAMETER">state_data_size</replaceable></term>
+    <listitem>
+     <para>
+      Approximate average size (in bytes) of aggregate's state value. 
+      Planner uses this value to approximate the memory required for 
+      the aggregation. If this value is not provided, a default value is 
+      used based on state_data_type.
+     </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
     <term><replaceable class="PARAMETER">ffunc</replaceable></term>
     <listitem>
      <para>
diff --git a/src/backend/catalog/pg_aggregate.c b/src/backend/catalog/pg_aggregate.c
index e80b600..d08e14a 100644
--- a/src/backend/catalog/pg_aggregate.c
+++ b/src/backend/catalog/pg_aggregate.c
@@ -51,6 +51,7 @@ AggregateCreate(const char *aggName,
 				List *aggfinalfnName,
 				List *aggsortopName,
 				Oid aggTransType,
+				int32 aggTransSpace,
 				const char *agginitval)
 {
 	Relation	aggdesc;
@@ -269,6 +270,7 @@ AggregateCreate(const char *aggName,
 	values[Anum_pg_aggregate_aggfinalfn - 1] = ObjectIdGetDatum(finalfn);
 	values[Anum_pg_aggregate_aggsortop - 1] = ObjectIdGetDatum(sortop);
 	values[Anum_pg_aggregate_aggtranstype - 1] = ObjectIdGetDatum(aggTransType);
+	values[Anum_pg_aggregate_aggtransspace - 1] = Int32GetDatum(aggTransSpace);
 	if (agginitval)
 		values[Anum_pg_aggregate_agginitval - 1] = CStringGetTextDatum(agginitval);
 	else
diff --git a/src/backend/commands/aggregatecmds.c b/src/backend/commands/aggregatecmds.c
index d34a102..6e5446a 100644
--- a/src/backend/commands/aggregatecmds.c
+++ b/src/backend/commands/aggregatecmds.c
@@ -62,6 +62,7 @@ DefineAggregate(List *name, List *args, bool oldstyle, List *parameters)
 	Oid		   *aggArgTypes;
 	int			numArgs;
 	Oid			transTypeId;
+	int32		transSpace = 0;
 	char		transTypeType;
 	ListCell   *pl;
 
@@ -96,6 +97,8 @@ DefineAggregate(List *name, List *args, bool oldstyle, List *parameters)
 			transType = defGetTypeName(defel);
 		else if (pg_strcasecmp(defel->defname, "stype1") == 0)
 			transType = defGetTypeName(defel);
+		else if (pg_strcasecmp(defel->defname, "sspace") == 0)
+			transSpace = defGetInt32(defel);
 		else if (pg_strcasecmp(defel->defname, "initcond") == 0)
 			initval = defGetString(defel);
 		else if (pg_strcasecmp(defel->defname, "initcond1") == 0)
@@ -225,5 +228,6 @@ DefineAggregate(List *name, List *args, bool oldstyle, List *parameters)
 						   finalfuncName,		/* final function name */
 						   sortoperatorName,	/* sort operator name */
 						   transTypeId,	/* transition data type */
+						   transSpace,			/* transition space */
 						   initval);	/* initial condition */
 }
diff --git a/src/backend/commands/define.c b/src/backend/commands/define.c
index 9fa222f..75f77da 100644
--- a/src/backend/commands/define.c
+++ b/src/backend/commands/define.c
@@ -165,6 +165,30 @@ defGetBoolean(DefElem *def)
 }
 
 /*
+ * Extract an int32 value from a DefElem.
+ */
+int32
+defGetInt32(DefElem *def)
+{
+	if (def->arg == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("%s requires an integer value",
+						def->defname)));
+	switch (nodeTag(def->arg))
+	{
+		case T_Integer:
+			return (int32) intVal(def->arg);
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+					 errmsg("%s requires an integer value",
+							def->defname)));
+	}
+	return 0;					/* keep compiler quiet */
+}
+
+/*
  * Extract an int64 value from a DefElem.
  */
 int64
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 657a18b..b5e2c01 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -461,6 +461,7 @@ count_agg_clauses_walker(Node *node, count_agg_clauses_context *context)
 		Oid			aggtransfn;
 		Oid			aggfinalfn;
 		Oid			aggtranstype;
+		int32 		aggtransspace;
 		QualCost	argcosts;
 		Oid		   *inputTypes;
 		int			numArguments;
@@ -478,6 +479,7 @@ count_agg_clauses_walker(Node *node, count_agg_clauses_context *context)
 		aggtransfn = aggform->aggtransfn;
 		aggfinalfn = aggform->aggfinalfn;
 		aggtranstype = aggform->aggtranstype;
+		aggtransspace = aggform->aggtransspace;
 		ReleaseSysCache(aggTuple);
 
 		/* count it */
@@ -524,13 +526,21 @@ count_agg_clauses_walker(Node *node, count_agg_clauses_context *context)
 			pfree(declaredArgTypes);
 		}
 
+		/* 
+		 * If approximate average space used by aggregate transition value is
+		 * specified in pg_aggregate, then use it for transitionSpace.
+		 */
+		if (aggtransspace > 0)
+		{
+			costs->transitionSpace += aggtransspace;
+		}
 		/*
 		 * If the transition type is pass-by-value then it doesn't add
 		 * anything to the required size of the hashtable.	If it is
 		 * pass-by-reference then we have to add the estimated size of the
 		 * value itself, plus palloc overhead.
 		 */
-		if (!get_typbyval(aggtranstype))
+		else if (!get_typbyval(aggtranstype))
 		{
 			int32		aggtranstypmod;
 			int32		avgwidth;
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 9458429..fd04c54 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -11268,12 +11268,14 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 	int			i_aggfinalfn;
 	int			i_aggsortop;
 	int			i_aggtranstype;
+	int 		i_aggtransspace;
 	int			i_agginitval;
 	int			i_convertok;
 	const char *aggtransfn;
 	const char *aggfinalfn;
 	const char *aggsortop;
 	const char *aggtranstype;
+	const char *aggtransspace;
 	const char *agginitval;
 	bool		convertok;
 
@@ -11291,12 +11293,24 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 	selectSourceSchema(fout, agginfo->aggfn.dobj.namespace->dobj.name);
 
 	/* Get aggregate-specific details */
-	if (fout->remoteVersion >= 80100)
+	if (fout->remoteVersion >= 90300)
+	{
+		appendPQExpBuffer(query, "SELECT aggtransfn, "
+						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
+						  "aggsortop::pg_catalog.regoperator, "
+						  "aggtransspace, agginitval, "
+						  "'t'::boolean AS convertok "
+					  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
+						  "WHERE a.aggfnoid = p.oid "
+						  "AND p.oid = '%u'::pg_catalog.oid",
+						  agginfo->aggfn.dobj.catId.oid);
+	}
+	else if (fout->remoteVersion >= 80100)
 	{
 		appendPQExpBuffer(query, "SELECT aggtransfn, "
 						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
 						  "aggsortop::pg_catalog.regoperator, "
-						  "agginitval, "
+						  "0 AS aggtransspace, agginitval, "
 						  "'t'::boolean AS convertok "
 					  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
 						  "WHERE a.aggfnoid = p.oid "
@@ -11308,7 +11322,7 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 		appendPQExpBuffer(query, "SELECT aggtransfn, "
 						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
 						  "0 AS aggsortop, "
-						  "agginitval, "
+						  "0 AS aggtransspace, agginitval, "
 						  "'t'::boolean AS convertok "
 					  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
 						  "WHERE a.aggfnoid = p.oid "
@@ -11320,7 +11334,7 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 		appendPQExpBuffer(query, "SELECT aggtransfn, aggfinalfn, "
 						  "format_type(aggtranstype, NULL) AS aggtranstype, "
 						  "0 AS aggsortop, "
-						  "agginitval, "
+						  "0 AS aggtransspace, agginitval, "
 						  "'t'::boolean AS convertok "
 						  "FROM pg_aggregate "
 						  "WHERE oid = '%u'::oid",
@@ -11332,7 +11346,7 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 						  "aggfinalfn, "
 						  "(SELECT typname FROM pg_type WHERE oid = aggtranstype1) AS aggtranstype, "
 						  "0 AS aggsortop, "
-						  "agginitval1 AS agginitval, "
+						  "0 AS aggtransspace, agginitval1 AS agginitval, "
 						  "(aggtransfn2 = 0 and aggtranstype2 = 0 and agginitval2 is null) AS convertok "
 						  "FROM pg_aggregate "
 						  "WHERE oid = '%u'::oid",
@@ -11345,6 +11359,7 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 	i_aggfinalfn = PQfnumber(res, "aggfinalfn");
 	i_aggsortop = PQfnumber(res, "aggsortop");
 	i_aggtranstype = PQfnumber(res, "aggtranstype");
+	i_aggtransspace = PQfnumber(res, "aggtransspace");
 	i_agginitval = PQfnumber(res, "agginitval");
 	i_convertok = PQfnumber(res, "convertok");
 
@@ -11352,6 +11367,7 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 	aggfinalfn = PQgetvalue(res, 0, i_aggfinalfn);
 	aggsortop = PQgetvalue(res, 0, i_aggsortop);
 	aggtranstype = PQgetvalue(res, 0, i_aggtranstype);
+	aggtransspace = PQgetvalue(res, 0, i_aggtransspace);
 	agginitval = PQgetvalue(res, 0, i_agginitval);
 	convertok = (PQgetvalue(res, 0, i_convertok)[0] == 't');
 
@@ -11388,6 +11404,12 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 						  fmtId(aggtranstype));
 	}
 
+	if (strcmp(aggtransspace, "0") != 0)
+	{
+		appendPQExpBuffer(details, ",\n    SSPACE = %s",
+						  aggtransspace);
+	}
+
 	if (!PQgetisnull(res, 0, i_agginitval))
 	{
 		appendPQExpBuffer(details, ",\n    INITCOND = ");
diff --git a/src/include/catalog/pg_aggregate.h b/src/include/catalog/pg_aggregate.h
index 6fb10a9..65ab160 100644
--- a/src/include/catalog/pg_aggregate.h
+++ b/src/include/catalog/pg_aggregate.h
@@ -32,6 +32,7 @@
  *	aggfinalfn			final function (0 if none)
  *	aggsortop			associated sort operator (0 if none)
  *	aggtranstype		type of aggregate's transition (state) data
+ *	aggtransspace		approximate size of aggregate transition state
  *	agginitval			initial value for transition state (can be NULL)
  * ----------------------------------------------------------------
  */
@@ -44,6 +45,7 @@ CATALOG(pg_aggregate,2600) BKI_WITHOUT_OIDS
 	regproc		aggfinalfn;
 	Oid			aggsortop;
 	Oid			aggtranstype;
+	int32 		aggtransspace;
 
 #ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	text		agginitval;
@@ -62,13 +64,14 @@ typedef FormData_pg_aggregate *Form_pg_aggregate;
  * ----------------
  */
 
-#define Natts_pg_aggregate				6
+#define Natts_pg_aggregate				7
 #define Anum_pg_aggregate_aggfnoid		1
 #define Anum_pg_aggregate_aggtransfn	2
 #define Anum_pg_aggregate_aggfinalfn	3
 #define Anum_pg_aggregate_aggsortop		4
 #define Anum_pg_aggregate_aggtranstype	5
-#define Anum_pg_aggregate_agginitval	6
+#define Anum_pg_aggregate_aggtransspace	6
+#define Anum_pg_aggregate_agginitval	7
 
 
 /* ----------------
@@ -77,163 +80,163 @@ typedef FormData_pg_aggregate *Form_pg_aggregate;
  */
 
 /* avg */
-DATA(insert ( 2100	int8_avg_accum	numeric_avg		0	1231	"{0,0}" ));
-DATA(insert ( 2101	int4_avg_accum	int8_avg		0	1016	"{0,0}" ));
-DATA(insert ( 2102	int2_avg_accum	int8_avg		0	1016	"{0,0}" ));
-DATA(insert ( 2103	numeric_avg_accum	numeric_avg		0	1231	"{0,0}" ));
-DATA(insert ( 2104	float4_accum	float8_avg		0	1022	"{0,0,0}" ));
-DATA(insert ( 2105	float8_accum	float8_avg		0	1022	"{0,0,0}" ));
-DATA(insert ( 2106	interval_accum	interval_avg	0	1187	"{0 second,0 second}" ));
+DATA(insert ( 2100	int8_avg_accum	numeric_avg		0	1231	0	"{0,0}" ));
+DATA(insert ( 2101	int4_avg_accum	int8_avg		0	1016	0	"{0,0}" ));
+DATA(insert ( 2102	int2_avg_accum	int8_avg		0	1016	0	"{0,0}" ));
+DATA(insert ( 2103	numeric_avg_accum	numeric_avg		0	1231	0	"{0,0}" ));
+DATA(insert ( 2104	float4_accum	float8_avg		0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2105	float8_accum	float8_avg		0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2106	interval_accum	interval_avg	0	1187	0	"{0 second,0 second}" ));
 
 /* sum */
-DATA(insert ( 2107	int8_sum		-				0	1700	_null_ ));
-DATA(insert ( 2108	int4_sum		-				0	20		_null_ ));
-DATA(insert ( 2109	int2_sum		-				0	20		_null_ ));
-DATA(insert ( 2110	float4pl		-				0	700		_null_ ));
-DATA(insert ( 2111	float8pl		-				0	701		_null_ ));
-DATA(insert ( 2112	cash_pl			-				0	790		_null_ ));
-DATA(insert ( 2113	interval_pl		-				0	1186	_null_ ));
-DATA(insert ( 2114	numeric_add		-				0	1700	_null_ ));
+DATA(insert ( 2107	int8_sum		-				0	1700	0	_null_ ));
+DATA(insert ( 2108	int4_sum		-				0	20		0	_null_ ));
+DATA(insert ( 2109	int2_sum		-				0	20		0	_null_ ));
+DATA(insert ( 2110	float4pl		-				0	700		0	_null_ ));
+DATA(insert ( 2111	float8pl		-				0	701		0	_null_ ));
+DATA(insert ( 2112	cash_pl			-				0	790		0	_null_ ));
+DATA(insert ( 2113	interval_pl		-				0	1186	0	_null_ ));
+DATA(insert ( 2114	numeric_add		-				0	1700	0	_null_ ));
 
 /* max */
-DATA(insert ( 2115	int8larger		-				413		20		_null_ ));
-DATA(insert ( 2116	int4larger		-				521		23		_null_ ));
-DATA(insert ( 2117	int2larger		-				520		21		_null_ ));
-DATA(insert ( 2118	oidlarger		-				610		26		_null_ ));
-DATA(insert ( 2119	float4larger	-				623		700		_null_ ));
-DATA(insert ( 2120	float8larger	-				674		701		_null_ ));
-DATA(insert ( 2121	int4larger		-				563		702		_null_ ));
-DATA(insert ( 2122	date_larger		-				1097	1082	_null_ ));
-DATA(insert ( 2123	time_larger		-				1112	1083	_null_ ));
-DATA(insert ( 2124	timetz_larger	-				1554	1266	_null_ ));
-DATA(insert ( 2125	cashlarger		-				903		790		_null_ ));
-DATA(insert ( 2126	timestamp_larger	-			2064	1114	_null_ ));
-DATA(insert ( 2127	timestamptz_larger	-			1324	1184	_null_ ));
-DATA(insert ( 2128	interval_larger -				1334	1186	_null_ ));
-DATA(insert ( 2129	text_larger		-				666		25		_null_ ));
-DATA(insert ( 2130	numeric_larger	-				1756	1700	_null_ ));
-DATA(insert ( 2050	array_larger	-				1073	2277	_null_ ));
-DATA(insert ( 2244	bpchar_larger	-				1060	1042	_null_ ));
-DATA(insert ( 2797	tidlarger		-				2800	27		_null_ ));
-DATA(insert ( 3526	enum_larger		-				3519	3500	_null_ ));
+DATA(insert ( 2115	int8larger		-				413		20		0	_null_ ));
+DATA(insert ( 2116	int4larger		-				521		23		0	_null_ ));
+DATA(insert ( 2117	int2larger		-				520		21		0	_null_ ));
+DATA(insert ( 2118	oidlarger		-				610		26		0	_null_ ));
+DATA(insert ( 2119	float4larger	-				623		700		0	_null_ ));
+DATA(insert ( 2120	float8larger	-				674		701		0	_null_ ));
+DATA(insert ( 2121	int4larger		-				563		702		0	_null_ ));
+DATA(insert ( 2122	date_larger		-				1097	1082	0	_null_ ));
+DATA(insert ( 2123	time_larger		-				1112	1083	0	_null_ ));
+DATA(insert ( 2124	timetz_larger	-				1554	1266	0	_null_ ));
+DATA(insert ( 2125	cashlarger		-				903		790		0	_null_ ));
+DATA(insert ( 2126	timestamp_larger	-			2064	1114	0	_null_ ));
+DATA(insert ( 2127	timestamptz_larger	-			1324	1184	0	_null_ ));
+DATA(insert ( 2128	interval_larger -				1334	1186	0	_null_ ));
+DATA(insert ( 2129	text_larger		-				666		25		0	_null_ ));
+DATA(insert ( 2130	numeric_larger	-				1756	1700	0	_null_ ));
+DATA(insert ( 2050	array_larger	-				1073	2277	0	_null_ ));
+DATA(insert ( 2244	bpchar_larger	-				1060	1042	0	_null_ ));
+DATA(insert ( 2797	tidlarger		-				2800	27		0	_null_ ));
+DATA(insert ( 3526	enum_larger		-				3519	3500	0	_null_ ));
 
 /* min */
-DATA(insert ( 2131	int8smaller		-				412		20		_null_ ));
-DATA(insert ( 2132	int4smaller		-				97		23		_null_ ));
-DATA(insert ( 2133	int2smaller		-				95		21		_null_ ));
-DATA(insert ( 2134	oidsmaller		-				609		26		_null_ ));
-DATA(insert ( 2135	float4smaller	-				622		700		_null_ ));
-DATA(insert ( 2136	float8smaller	-				672		701		_null_ ));
-DATA(insert ( 2137	int4smaller		-				562		702		_null_ ));
-DATA(insert ( 2138	date_smaller	-				1095	1082	_null_ ));
-DATA(insert ( 2139	time_smaller	-				1110	1083	_null_ ));
-DATA(insert ( 2140	timetz_smaller	-				1552	1266	_null_ ));
-DATA(insert ( 2141	cashsmaller		-				902		790		_null_ ));
-DATA(insert ( 2142	timestamp_smaller	-			2062	1114	_null_ ));
-DATA(insert ( 2143	timestamptz_smaller -			1322	1184	_null_ ));
-DATA(insert ( 2144	interval_smaller	-			1332	1186	_null_ ));
-DATA(insert ( 2145	text_smaller	-				664		25		_null_ ));
-DATA(insert ( 2146	numeric_smaller -				1754	1700	_null_ ));
-DATA(insert ( 2051	array_smaller	-				1072	2277	_null_ ));
-DATA(insert ( 2245	bpchar_smaller	-				1058	1042	_null_ ));
-DATA(insert ( 2798	tidsmaller		-				2799	27		_null_ ));
-DATA(insert ( 3527	enum_smaller	-				3518	3500	_null_ ));
+DATA(insert ( 2131	int8smaller		-				412		20		0	_null_ ));
+DATA(insert ( 2132	int4smaller		-				97		23		0	_null_ ));
+DATA(insert ( 2133	int2smaller		-				95		21		0	_null_ ));
+DATA(insert ( 2134	oidsmaller		-				609		26		0	_null_ ));
+DATA(insert ( 2135	float4smaller	-				622		700		0	_null_ ));
+DATA(insert ( 2136	float8smaller	-				672		701		0	_null_ ));
+DATA(insert ( 2137	int4smaller		-				562		702		0	_null_ ));
+DATA(insert ( 2138	date_smaller	-				1095	1082	0	_null_ ));
+DATA(insert ( 2139	time_smaller	-				1110	1083	0	_null_ ));
+DATA(insert ( 2140	timetz_smaller	-				1552	1266	0	_null_ ));
+DATA(insert ( 2141	cashsmaller		-				902		790		0	_null_ ));
+DATA(insert ( 2142	timestamp_smaller	-			2062	1114	0	_null_ ));
+DATA(insert ( 2143	timestamptz_smaller -			1322	1184	0	_null_ ));
+DATA(insert ( 2144	interval_smaller	-			1332	1186	0	_null_ ));
+DATA(insert ( 2145	text_smaller	-				664		25		0	_null_ ));
+DATA(insert ( 2146	numeric_smaller -				1754	1700	0	_null_ ));
+DATA(insert ( 2051	array_smaller	-				1072	2277	0	_null_ ));
+DATA(insert ( 2245	bpchar_smaller	-				1058	1042	0	_null_ ));
+DATA(insert ( 2798	tidsmaller		-				2799	27		0	_null_ ));
+DATA(insert ( 3527	enum_smaller	-				3518	3500	0	_null_ ));
 
 /* count */
-DATA(insert ( 2147	int8inc_any		-				0		20		"0" ));
-DATA(insert ( 2803	int8inc			-				0		20		"0" ));
+DATA(insert ( 2147	int8inc_any		-				0		20		0	"0" ));
+DATA(insert ( 2803	int8inc			-				0		20		0	"0" ));
 
 /* var_pop */
-DATA(insert ( 2718	int8_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
-DATA(insert ( 2719	int4_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
-DATA(insert ( 2720	int2_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
-DATA(insert ( 2721	float4_accum	float8_var_pop 0	1022	"{0,0,0}" ));
-DATA(insert ( 2722	float8_accum	float8_var_pop 0	1022	"{0,0,0}" ));
-DATA(insert ( 2723	numeric_accum  numeric_var_pop 0	1231	"{0,0,0}" ));
+DATA(insert ( 2718	int8_accum	numeric_var_pop 0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2719	int4_accum	numeric_var_pop 0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2720	int2_accum	numeric_var_pop 0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2721	float4_accum	float8_var_pop 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2722	float8_accum	float8_var_pop 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2723	numeric_accum  numeric_var_pop 0	1231	0	"{0,0,0}" ));
 
 /* var_samp */
-DATA(insert ( 2641	int8_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2642	int4_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2643	int2_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2644	float4_accum	float8_var_samp 0	1022	"{0,0,0}" ));
-DATA(insert ( 2645	float8_accum	float8_var_samp 0	1022	"{0,0,0}" ));
-DATA(insert ( 2646	numeric_accum  numeric_var_samp 0	1231	"{0,0,0}" ));
+DATA(insert ( 2641	int8_accum	numeric_var_samp	0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2642	int4_accum	numeric_var_samp	0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2643	int2_accum	numeric_var_samp	0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2644	float4_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2645	float8_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2646	numeric_accum  numeric_var_samp 0	1231	0	"{0,0,0}" ));
 
 /* variance: historical Postgres syntax for var_samp */
-DATA(insert ( 2148	int8_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2149	int4_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2150	int2_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2151	float4_accum	float8_var_samp 0	1022	"{0,0,0}" ));
-DATA(insert ( 2152	float8_accum	float8_var_samp 0	1022	"{0,0,0}" ));
-DATA(insert ( 2153	numeric_accum  numeric_var_samp 0	1231	"{0,0,0}" ));
+DATA(insert ( 2148	int8_accum	numeric_var_samp	0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2149	int4_accum	numeric_var_samp	0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2150	int2_accum	numeric_var_samp	0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2151	float4_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2152	float8_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2153	numeric_accum  numeric_var_samp 0	1231	0	"{0,0,0}" ));
 
 /* stddev_pop */
-DATA(insert ( 2724	int8_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
-DATA(insert ( 2725	int4_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
-DATA(insert ( 2726	int2_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
-DATA(insert ( 2727	float4_accum	float8_stddev_pop	0	1022	"{0,0,0}" ));
-DATA(insert ( 2728	float8_accum	float8_stddev_pop	0	1022	"{0,0,0}" ));
-DATA(insert ( 2729	numeric_accum	numeric_stddev_pop	0	1231	"{0,0,0}" ));
+DATA(insert ( 2724	int8_accum	numeric_stddev_pop		0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2725	int4_accum	numeric_stddev_pop		0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2726	int2_accum	numeric_stddev_pop		0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2727	float4_accum	float8_stddev_pop	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2728	float8_accum	float8_stddev_pop	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2729	numeric_accum	numeric_stddev_pop	0	1231	0	"{0,0,0}" ));
 
 /* stddev_samp */
-DATA(insert ( 2712	int8_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2713	int4_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2714	int2_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2715	float4_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
-DATA(insert ( 2716	float8_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
-DATA(insert ( 2717	numeric_accum	numeric_stddev_samp 0	1231	"{0,0,0}" ));
+DATA(insert ( 2712	int8_accum	numeric_stddev_samp		0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2713	int4_accum	numeric_stddev_samp		0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2714	int2_accum	numeric_stddev_samp		0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2715	float4_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2716	float8_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2717	numeric_accum	numeric_stddev_samp 0	1231	0	"{0,0,0}" ));
 
 /* stddev: historical Postgres syntax for stddev_samp */
-DATA(insert ( 2154	int8_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2155	int4_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2156	int2_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2157	float4_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
-DATA(insert ( 2158	float8_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
-DATA(insert ( 2159	numeric_accum	numeric_stddev_samp 0	1231	"{0,0,0}" ));
+DATA(insert ( 2154	int8_accum	numeric_stddev_samp		0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2155	int4_accum	numeric_stddev_samp		0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2156	int2_accum	numeric_stddev_samp		0	1231	0	"{0,0,0}" ));
+DATA(insert ( 2157	float4_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2158	float8_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2159	numeric_accum	numeric_stddev_samp 0	1231	0	"{0,0,0}" ));
 
 /* SQL2003 binary regression aggregates */
-DATA(insert ( 2818	int8inc_float8_float8		-				0	20		"0" ));
-DATA(insert ( 2819	float8_regr_accum	float8_regr_sxx			0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2820	float8_regr_accum	float8_regr_syy			0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2821	float8_regr_accum	float8_regr_sxy			0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2822	float8_regr_accum	float8_regr_avgx		0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2823	float8_regr_accum	float8_regr_avgy		0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2824	float8_regr_accum	float8_regr_r2			0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2825	float8_regr_accum	float8_regr_slope		0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2826	float8_regr_accum	float8_regr_intercept	0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2827	float8_regr_accum	float8_covar_pop		0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2828	float8_regr_accum	float8_covar_samp		0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2829	float8_regr_accum	float8_corr				0	1022	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2818	int8inc_float8_float8		-				0	20		0	"0" ));
+DATA(insert ( 2819	float8_regr_accum	float8_regr_sxx			0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2820	float8_regr_accum	float8_regr_syy			0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2821	float8_regr_accum	float8_regr_sxy			0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2822	float8_regr_accum	float8_regr_avgx		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2823	float8_regr_accum	float8_regr_avgy		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2824	float8_regr_accum	float8_regr_r2			0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2825	float8_regr_accum	float8_regr_slope		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2826	float8_regr_accum	float8_regr_intercept	0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2827	float8_regr_accum	float8_covar_pop		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2828	float8_regr_accum	float8_covar_samp		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2829	float8_regr_accum	float8_corr				0	1022	0	"{0,0,0,0,0,0}" ));
 
 /* boolean-and and boolean-or */
-DATA(insert ( 2517	booland_statefunc	-			58	16		_null_ ));
-DATA(insert ( 2518	boolor_statefunc	-			59	16		_null_ ));
-DATA(insert ( 2519	booland_statefunc	-			58	16		_null_ ));
+DATA(insert ( 2517	booland_statefunc	-			58	16		0	_null_ ));
+DATA(insert ( 2518	boolor_statefunc	-			59	16		0	_null_ ));
+DATA(insert ( 2519	booland_statefunc	-			58	16		0	_null_ ));
 
 /* bitwise integer */
-DATA(insert ( 2236 int2and		  -					0	21		_null_ ));
-DATA(insert ( 2237 int2or		  -					0	21		_null_ ));
-DATA(insert ( 2238 int4and		  -					0	23		_null_ ));
-DATA(insert ( 2239 int4or		  -					0	23		_null_ ));
-DATA(insert ( 2240 int8and		  -					0	20		_null_ ));
-DATA(insert ( 2241 int8or		  -					0	20		_null_ ));
-DATA(insert ( 2242 bitand		  -					0	1560	_null_ ));
-DATA(insert ( 2243 bitor		  -					0	1560	_null_ ));
+DATA(insert ( 2236 int2and		  -					0	21		0	_null_ ));
+DATA(insert ( 2237 int2or		  -					0	21		0	_null_ ));
+DATA(insert ( 2238 int4and		  -					0	23		0	_null_ ));
+DATA(insert ( 2239 int4or		  -					0	23		0	_null_ ));
+DATA(insert ( 2240 int8and		  -					0	20		0	_null_ ));
+DATA(insert ( 2241 int8or		  -					0	20		0	_null_ ));
+DATA(insert ( 2242 bitand		  -					0	1560	0	_null_ ));
+DATA(insert ( 2243 bitor		  -					0	1560	0	_null_ ));
 
 /* xml */
-DATA(insert ( 2901 xmlconcat2	  -					0	142		_null_ ));
+DATA(insert ( 2901 xmlconcat2	  -					0	142		0	_null_ ));
 
 /* array */
-DATA(insert ( 2335	array_agg_transfn	array_agg_finalfn		0	2281	_null_ ));
+DATA(insert ( 2335	array_agg_transfn	array_agg_finalfn		0	2281	0	_null_ ));
 
 /* text */
-DATA(insert ( 3538	string_agg_transfn	string_agg_finalfn		0	2281	_null_ ));
+DATA(insert ( 3538	string_agg_transfn	string_agg_finalfn		0	2281	0	_null_ ));
 
 /* bytea */
-DATA(insert ( 3545	bytea_string_agg_transfn	bytea_string_agg_finalfn		0	2281	_null_ ));
+DATA(insert ( 3545	bytea_string_agg_transfn	bytea_string_agg_finalfn		0	2281	0	_null_ ));
 
 /* json */
-DATA(insert ( 3175	json_agg_transfn	json_agg_finalfn		0	2281	_null_ ));
+DATA(insert ( 3175	json_agg_transfn	json_agg_finalfn		0	2281	0	_null_ ));
 
 /*
  * prototypes for functions in pg_aggregate.c
@@ -246,6 +249,7 @@ extern Oid AggregateCreate(const char *aggName,
 				List *aggfinalfnName,
 				List *aggsortopName,
 				Oid aggTransType,
+				int32 aggTransSpace,
 				const char *agginitval);
 
 #endif   /* PG_AGGREGATE_H */
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index 62515b2..3abc89b 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -122,6 +122,7 @@ extern Datum transformGenericOptions(Oid catalogId,
 extern char *defGetString(DefElem *def);
 extern double defGetNumeric(DefElem *def);
 extern bool defGetBoolean(DefElem *def);
+extern int32 defGetInt32(DefElem *def);
 extern int64 defGetInt64(DefElem *def);
 extern List *defGetQualifiedName(DefElem *def);
 extern TypeName *defGetTypeName(DefElem *def);

diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 6715782..1fae7db 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -373,6 +373,12 @@
       <entry>Data type of the aggregate function's internal transition (state) data</entry>
      </row>
      <row>
+      <entry><structfield>aggtransspace</structfield></entry>
+      <entry><type>int4</type></entry>
+      <entry></entry>
+      <entry>Approximation for the average size of the aggregate function's internal transition (state) data</entry>
+     </row>
+     <row>
       <entry><structfield>agginitval</structfield></entry>
       <entry><type>text</type></entry>
       <entry></entry>
diff --git a/doc/src/sgml/ref/create_aggregate.sgml b/doc/src/sgml/ref/create_aggregate.sgml
index d5e4e27..594d095 100644
--- a/doc/src/sgml/ref/create_aggregate.sgml
+++ b/doc/src/sgml/ref/create_aggregate.sgml
@@ -24,6 +24,7 @@ PostgreSQL documentation
 CREATE AGGREGATE <replaceable class="PARAMETER">name</replaceable> ( <replaceable class="PARAMETER">input_data_type</replaceable> [ , ... ] ) (
     SFUNC = <replaceable class="PARAMETER">sfunc</replaceable>,
     STYPE = <replaceable class="PARAMETER">state_data_type</replaceable>
+    [ , SSPACE = <replaceable class="PARAMETER">state_data_size</replaceable> ]
     [ , FINALFUNC = <replaceable class="PARAMETER">ffunc</replaceable> ]
     [ , INITCOND = <replaceable class="PARAMETER">initial_condition</replaceable> ]
     [ , SORTOP = <replaceable class="PARAMETER">sort_operator</replaceable> ]
@@ -35,6 +36,7 @@ CREATE AGGREGATE <replaceable class="PARAMETER">name</replaceable> (
     BASETYPE = <replaceable class="PARAMETER">base_type</replaceable>,
     SFUNC = <replaceable class="PARAMETER">sfunc</replaceable>,
     STYPE = <replaceable class="PARAMETER">state_data_type</replaceable>
+    [ , SSPACE = <replaceable class="PARAMETER">state_data_size</replaceable> ]
     [ , FINALFUNC = <replaceable class="PARAMETER">ffunc</replaceable> ]
     [ , INITCOND = <replaceable class="PARAMETER">initial_condition</replaceable> ]
     [ , SORTOP = <replaceable class="PARAMETER">sort_operator</replaceable> ]
@@ -241,6 +243,18 @@ SELECT col FROM tab ORDER BY col USING sortop LIMIT 1;
    </varlistentry>
 
    <varlistentry>
+    <term><replaceable class="PARAMETER">state_data_size</replaceable></term>
+    <listitem>
+     <para>
+      Approximate average size (in bytes) of aggregate's state value. 
+      Planner uses this value to approximate the memory required for 
+      the aggregation. If this value is not provided, a default value is 
+      used based on state_data_type.
+     </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
     <term><replaceable class="PARAMETER">ffunc</replaceable></term>
     <listitem>
      <para>
diff --git a/src/backend/catalog/pg_aggregate.c b/src/backend/catalog/pg_aggregate.c
index e80b600..d08e14a 100644
--- a/src/backend/catalog/pg_aggregate.c
+++ b/src/backend/catalog/pg_aggregate.c
@@ -51,6 +51,7 @@ AggregateCreate(const char *aggName,
 				List *aggfinalfnName,
 				List *aggsortopName,
 				Oid aggTransType,
+				int32 aggTransSpace,
 				const char *agginitval)
 {
 	Relation	aggdesc;
@@ -269,6 +270,7 @@ AggregateCreate(const char *aggName,
 	values[Anum_pg_aggregate_aggfinalfn - 1] = ObjectIdGetDatum(finalfn);
 	values[Anum_pg_aggregate_aggsortop - 1] = ObjectIdGetDatum(sortop);
 	values[Anum_pg_aggregate_aggtranstype - 1] = ObjectIdGetDatum(aggTransType);
+	values[Anum_pg_aggregate_aggtransspace - 1] = Int32GetDatum(aggTransSpace);
 	if (agginitval)
 		values[Anum_pg_aggregate_agginitval - 1] = CStringGetTextDatum(agginitval);
 	else
diff --git a/src/backend/commands/aggregatecmds.c b/src/backend/commands/aggregatecmds.c
index 4a03786..656bf7a 100644
--- a/src/backend/commands/aggregatecmds.c
+++ b/src/backend/commands/aggregatecmds.c
@@ -62,6 +62,7 @@ DefineAggregate(List *name, List *args, bool oldstyle, List *parameters)
 	Oid		   *aggArgTypes;
 	int			numArgs;
 	Oid			transTypeId;
+	int32		transSpace = 0;
 	char		transTypeType;
 	ListCell   *pl;
 
@@ -96,6 +97,8 @@ DefineAggregate(List *name, List *args, bool oldstyle, List *parameters)
 			transType = defGetTypeName(defel);
 		else if (pg_strcasecmp(defel->defname, "stype1") == 0)
 			transType = defGetTypeName(defel);
+		else if (pg_strcasecmp(defel->defname, "sspace") == 0)
+			transSpace = defGetInt32(defel);
 		else if (pg_strcasecmp(defel->defname, "initcond") == 0)
 			initval = defGetString(defel);
 		else if (pg_strcasecmp(defel->defname, "initcond1") == 0)
@@ -225,5 +228,6 @@ DefineAggregate(List *name, List *args, bool oldstyle, List *parameters)
 						   finalfuncName,		/* final function name */
 						   sortoperatorName,	/* sort operator name */
 						   transTypeId, /* transition data type */
+						   transSpace,			/* transition space */
 						   initval);	/* initial condition */
 }
diff --git a/src/backend/commands/define.c b/src/backend/commands/define.c
index 9fa222f..75f77da 100644
--- a/src/backend/commands/define.c
+++ b/src/backend/commands/define.c
@@ -165,6 +165,30 @@ defGetBoolean(DefElem *def)
 }
 
 /*
+ * Extract an int32 value from a DefElem.
+ */
+int32
+defGetInt32(DefElem *def)
+{
+	if (def->arg == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("%s requires an integer value",
+						def->defname)));
+	switch (nodeTag(def->arg))
+	{
+		case T_Integer:
+			return (int32) intVal(def->arg);
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+					 errmsg("%s requires an integer value",
+							def->defname)));
+	}
+	return 0;					/* keep compiler quiet */
+}
+
+/*
  * Extract an int64 value from a DefElem.
  */
 int64
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 6d5b204..5d8f56d 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -461,6 +461,7 @@ count_agg_clauses_walker(Node *node, count_agg_clauses_context *context)
 		Oid			aggtransfn;
 		Oid			aggfinalfn;
 		Oid			aggtranstype;
+		int32 		aggtransspace;
 		QualCost	argcosts;
 		Oid		   *inputTypes;
 		int			numArguments;
@@ -478,6 +479,7 @@ count_agg_clauses_walker(Node *node, count_agg_clauses_context *context)
 		aggtransfn = aggform->aggtransfn;
 		aggfinalfn = aggform->aggfinalfn;
 		aggtranstype = aggform->aggtranstype;
+		aggtransspace = aggform->aggtransspace;
 		ReleaseSysCache(aggTuple);
 
 		/* count it */
@@ -524,13 +526,21 @@ count_agg_clauses_walker(Node *node, count_agg_clauses_context *context)
 			pfree(declaredArgTypes);
 		}
 
+		/* 
+		 * If approximate average space used by aggregate transition value is
+		 * specified in pg_aggregate, then use it for transitionSpace.
+		 */
+		if (aggtransspace > 0)
+		{
+			costs->transitionSpace += aggtransspace;
+		}
 		/*
 		 * If the transition type is pass-by-value then it doesn't add
 		 * anything to the required size of the hashtable.	If it is
 		 * pass-by-reference then we have to add the estimated size of the
 		 * value itself, plus palloc overhead.
 		 */
-		if (!get_typbyval(aggtranstype))
+		else if (!get_typbyval(aggtranstype))
 		{
 			int32		aggtranstypmod;
 			int32		avgwidth;
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index b4d6394..9a4706b 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -2464,108 +2464,157 @@ numeric_float4(PG_FUNCTION_ARGS)
  *
  * Aggregate functions
  *
- * The transition datatype for all these aggregates is a 3-element array
- * of Numeric, holding the values N, sum(X), sum(X*X) in that order.
- *
- * We represent N as a numeric mainly to avoid having to build a special
- * datatype; it's unlikely it'd overflow an int4, but ...
+ * The transition datatype for all these aggregates is a pointer to 
+ * a struct NumericAggState allocated in the aggregate context.
  *
  * ----------------------------------------------------------------------
  */
 
-static ArrayType *
-do_numeric_accum(ArrayType *transarray, Numeric newval)
+typedef struct NumericAggState
+{
+	bool 			first;
+	bool 			isNaN;
+	uint64			N;
+	NumericVar 		sumX;
+	NumericVar 		sumX2;
+	bool 			calcSumX2;
+	MemoryContext 	agg_context;
+} NumericAggState;
+
+
+static NumericAggState *
+makeNumericAggState(FunctionCallInfo fcinfo, bool calcSumX2)
 {
-	Datum	   *transdatums;
-	int			ndatums;
-	Datum		N,
-				sumX,
-				sumX2;
-	ArrayType  *result;
-
-	/* We assume the input is array of numeric */
-	deconstruct_array(transarray,
-					  NUMERICOID, -1, false, 'i',
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 3)
-		elog(ERROR, "expected 3-element numeric array");
-	N = transdatums[0];
-	sumX = transdatums[1];
-	sumX2 = transdatums[2];
-
-	N = DirectFunctionCall1(numeric_inc, N);
-	sumX = DirectFunctionCall2(numeric_add, sumX,
-							   NumericGetDatum(newval));
-	sumX2 = DirectFunctionCall2(numeric_add, sumX2,
-								DirectFunctionCall2(numeric_mul,
-													NumericGetDatum(newval),
-													NumericGetDatum(newval)));
-
-	transdatums[0] = N;
-	transdatums[1] = sumX;
-	transdatums[2] = sumX2;
-
-	result = construct_array(transdatums, 3,
-							 NUMERICOID, -1, false, 'i');
+	NumericAggState 	*state;
+	MemoryContext 		 agg_context;
+	MemoryContext 		 old_context;
 
-	return result;
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+	{
+		elog(ERROR, "this is called in non-aggregate context");
+	}
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = palloc0(sizeof(NumericAggState));
+	state->first = true;
+	state->calcSumX2 = calcSumX2;
+	state->agg_context = agg_context;
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
 }
 
-/*
- * Improve avg performance by not caclulating sum(X*X).
- */
-static ArrayType *
-do_numeric_avg_accum(ArrayType *transarray, Numeric newval)
+
+static void
+do_numeric_accum(NumericAggState *state, Numeric newval)
 {
-	Datum	   *transdatums;
-	int			ndatums;
-	Datum		N,
-				sumX;
-	ArrayType  *result;
-
-	/* We assume the input is array of numeric */
-	deconstruct_array(transarray,
-					  NUMERICOID, -1, false, 'i',
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element numeric array");
-	N = transdatums[0];
-	sumX = transdatums[1];
-
-	N = DirectFunctionCall1(numeric_inc, N);
-	sumX = DirectFunctionCall2(numeric_add, sumX,
-							   NumericGetDatum(newval));
-
-	transdatums[0] = N;
-	transdatums[1] = sumX;
-
-	result = construct_array(transdatums, 2,
-							 NUMERICOID, -1, false, 'i');
+	NumericVar 		X;
+	NumericVar 		X2;
+	MemoryContext 	old_context;
+	bool 			first;
+	
+	first = state->first;
+	state->first = false;
+	state->N++;
+
+	if (state->isNaN || NUMERIC_IS_NAN(newval))
+	{
+		state->isNaN = true;
+		return;
+	}
 
-	return result;
+	init_var_from_num(newval, &X);
+
+	if (state->calcSumX2)
+	{
+		init_var(&X2);
+		mul_var(&X, &X, &X2, X.dscale * 2);
+	}
+
+	old_context = MemoryContextSwitchTo(state->agg_context);
+
+	if (!first)
+	{
+		NumericVar preSumX;
+
+		memcpy(&preSumX, &(state->sumX), sizeof(NumericVar));
+		init_var(&(state->sumX));
+		add_var(&X, &preSumX, &(state->sumX));
+		free_var(&preSumX);
+
+		if (state->calcSumX2)
+		{
+			NumericVar preSumX2;
+
+			memcpy(&preSumX2, &(state->sumX2), sizeof(NumericVar));
+			init_var(&(state->sumX2));
+			add_var(&X2, &preSumX2, &(state->sumX2));
+			free_var(&preSumX2);
+		}
+	}
+	else
+	{
+		set_var_from_var(&X, &(state->sumX));
+
+		if (state->calcSumX2)
+			set_var_from_var(&X2, &(state->sumX2));
+	}
+
+	MemoryContextSwitchTo(old_context);
 }
 
+
 Datum
 numeric_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Numeric		newval = PG_GETARG_NUMERIC(1);
+	NumericAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
 
-	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
+	if (!PG_ARGISNULL(1))
+	{
+		/* On the first time through, create the state variable. */
+		if (state == NULL)
+			state = makeNumericAggState(fcinfo, true);
+		
+		do_numeric_accum(state, PG_GETARG_NUMERIC(1));
+	}
+
+	if (state == NULL)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_POINTER(state);
 }
 
+
 /*
  * Optimized case for average of numeric.
  */
 Datum
 numeric_avg_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Numeric		newval = PG_GETARG_NUMERIC(1);
+	NumericAggState *state;
 
-	PG_RETURN_ARRAYTYPE_P(do_numeric_avg_accum(transarray, newval));
+	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+	if (!PG_ARGISNULL(1))
+	{
+		/* On the first time through, create the state variable. */
+		if (state == NULL)
+			state = makeNumericAggState(fcinfo, false);
+		
+		do_numeric_accum(state, PG_GETARG_NUMERIC(1));
+	}
+
+	if (state == NULL)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_POINTER(state);
 }
 
+
 /*
  * Integer data types all use Numeric accumulators to share code and
  * avoid risk of overflow.	For int2 and int4 inputs, Numeric accumulation
@@ -2578,87 +2627,150 @@ numeric_avg_accum(PG_FUNCTION_ARGS)
 Datum
 int2_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum		newval2 = PG_GETARG_DATUM(1);
-	Numeric		newval;
+	NumericAggState *state;
 
-	newval = DatumGetNumeric(DirectFunctionCall1(int2_numeric, newval2));
+	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
 
-	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
+	if (!PG_ARGISNULL(1))
+	{
+		Datum		newval2 = PG_GETARG_DATUM(1);
+		Numeric		newval;
+
+		/* On the first time through, create the state variable. */
+		if (state == NULL)
+			state = makeNumericAggState(fcinfo, true);
+		
+		newval = DatumGetNumeric(DirectFunctionCall1(int2_numeric, newval2));
+		do_numeric_accum(state, newval);
+	}
+
+	if (state == NULL)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_POINTER(state);
 }
 
+
 Datum
 int4_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum		newval4 = PG_GETARG_DATUM(1);
-	Numeric		newval;
+	NumericAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
 
-	newval = DatumGetNumeric(DirectFunctionCall1(int4_numeric, newval4));
+	if (!PG_ARGISNULL(1))
+	{
+		Datum		newval4 = PG_GETARG_DATUM(1);
+		Numeric		newval;
+
+		/* On the first time through, create the state variable. */
+		if (state == NULL)
+			state = makeNumericAggState(fcinfo, true);
+		
+		newval = DatumGetNumeric(DirectFunctionCall1(int4_numeric, newval4));
+		do_numeric_accum(state, newval);
+	}
 
-	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
+	if (state == NULL)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_POINTER(state);
 }
 
+
 Datum
 int8_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum		newval8 = PG_GETARG_DATUM(1);
-	Numeric		newval;
+	NumericAggState *state;
 
-	newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
+	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+	if (!PG_ARGISNULL(1))
+	{
+		Datum		newval8 = PG_GETARG_DATUM(1);
+		Numeric		newval;
+
+		/* On the first time through, create the state variable. */
+		if (state == NULL)
+			state = makeNumericAggState(fcinfo, true);
+		
+		newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
+		do_numeric_accum(state, newval);
+	}
 
-	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
+	if (state == NULL)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_POINTER(state);
 }
 
+
 /*
  * Optimized case for average of int8.
  */
 Datum
 int8_avg_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum		newval8 = PG_GETARG_DATUM(1);
-	Numeric		newval;
-
-	newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
+	NumericAggState *state;	
+	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
 
-	PG_RETURN_ARRAYTYPE_P(do_numeric_avg_accum(transarray, newval));
+	if (!PG_ARGISNULL(1))
+	{
+		Datum		newval8 = PG_GETARG_DATUM(1);
+		Numeric		newval;
+
+		/* On the first time through, create the state variable. */
+		if (state == NULL)
+			state = makeNumericAggState(fcinfo, false);
+		
+		newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
+		do_numeric_accum(state, newval);
+	}
+ 
+	if (state == NULL)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_POINTER(state);
 }
 
 
 Datum
 numeric_avg(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Numeric		N,
-				sumX;
-
-	/* We assume the input is array of numeric */
-	deconstruct_array(transarray,
-					  NUMERICOID, -1, false, 'i',
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element numeric array");
-	N = DatumGetNumeric(transdatums[0]);
-	sumX = DatumGetNumeric(transdatums[1]);
+	Datum 		 		N_datum;
+	Datum 				sumX_datum;
+	NumericAggState 	*state;
 
-	/* SQL defines AVG of no values to be NULL */
-	/* N is zero iff no digits (cf. numeric_uminus) */
-	if (NUMERIC_NDIGITS(N) == 0)
+	if (PG_ARGISNULL(0))
 		PG_RETURN_NULL();
 
-	PG_RETURN_DATUM(DirectFunctionCall2(numeric_div,
-										NumericGetDatum(sumX),
-										NumericGetDatum(N)));
+	state = (NumericAggState *) PG_GETARG_POINTER(0);
+
+	N_datum = DirectFunctionCall1(int8_numeric, Int64GetDatum(state->N));
+	sumX_datum = NumericGetDatum(make_result(&state->sumX));
+
+	PG_RETURN_DATUM(DirectFunctionCall2(numeric_div, sumX_datum, N_datum));
 }
 
+
+Datum
+numeric_sum(PG_FUNCTION_ARGS)
+{
+	NumericAggState 	*state;
+
+	if (PG_ARGISNULL(0))
+		PG_RETURN_NULL();
+ 
+	state = (NumericAggState *) PG_GETARG_POINTER(0);
+
+	PG_RETURN_NUMERIC(make_result(&(state->sumX)));
+}
+
+
 /*
  * Workhorse routine for the standard deviance and variance
- * aggregates. 'transarray' is the aggregate's transition
- * array. 'variance' specifies whether we should calculate the
+ * aggregates. 'state' is aggregate's transition state.
+ * 'variance' specifies whether we should calculate the
  * variance or the standard deviation. 'sample' indicates whether the
  * caller is interested in the sample or the population
  * variance/stddev.
@@ -2667,16 +2779,11 @@ numeric_avg(PG_FUNCTION_ARGS)
  * *is_null is set to true and NULL is returned.
  */
 static Numeric
-numeric_stddev_internal(ArrayType *transarray,
+numeric_stddev_internal(NumericAggState *state,
 						bool variance, bool sample,
 						bool *is_null)
 {
-	Datum	   *transdatums;
-	int			ndatums;
-	Numeric		N,
-				sumX,
-				sumX2,
-				res;
+	Numeric		res;
 	NumericVar	vN,
 				vsumX,
 				vsumX2,
@@ -2684,22 +2791,24 @@ numeric_stddev_internal(ArrayType *transarray,
 	NumericVar *comp;
 	int			rscale;
 
+	if (state == NULL)
+	{
+		*is_null = true;
+		return NULL;
+	}
+
 	*is_null = false;
 
-	/* We assume the input is array of numeric */
-	deconstruct_array(transarray,
-					  NUMERICOID, -1, false, 'i',
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 3)
-		elog(ERROR, "expected 3-element numeric array");
-	N = DatumGetNumeric(transdatums[0]);
-	sumX = DatumGetNumeric(transdatums[1]);
-	sumX2 = DatumGetNumeric(transdatums[2]);
-
-	if (NUMERIC_IS_NAN(N) || NUMERIC_IS_NAN(sumX) || NUMERIC_IS_NAN(sumX2))
+	if (state->isNaN)
 		return make_result(&const_nan);
 
-	init_var_from_num(N, &vN);
+	init_var(&vN);
+	init_var(&vsumX);
+	init_var(&vsumX2);
+
+	int8_to_numericvar(state->N, &vN);
+	set_var_from_var(&(state->sumX), &vsumX);
+	set_var_from_var(&(state->sumX2), &vsumX2);
 
 	/*
 	 * Sample stddev and variance are undefined when N <= 1; population stddev
@@ -2719,8 +2828,8 @@ numeric_stddev_internal(ArrayType *transarray,
 	init_var(&vNminus1);
 	sub_var(&vN, &const_one, &vNminus1);
 
-	init_var_from_num(sumX, &vsumX);
-	init_var_from_num(sumX2, &vsumX2);
+	set_var_from_var(&(state->sumX), &vsumX);
+	set_var_from_var(&(state->sumX2), &vsumX2);
 
 	/* compute rscale for mul_var calls */
 	rscale = vsumX.dscale * 2;
@@ -2761,7 +2870,7 @@ numeric_var_samp(PG_FUNCTION_ARGS)
 	Numeric		res;
 	bool		is_null;
 
-	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
+	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
 								  true, true, &is_null);
 
 	if (is_null)
@@ -2776,7 +2885,7 @@ numeric_stddev_samp(PG_FUNCTION_ARGS)
 	Numeric		res;
 	bool		is_null;
 
-	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
+	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
 								  false, true, &is_null);
 
 	if (is_null)
@@ -2791,7 +2900,7 @@ numeric_var_pop(PG_FUNCTION_ARGS)
 	Numeric		res;
 	bool		is_null;
 
-	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
+	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
 								  true, false, &is_null);
 
 	if (is_null)
@@ -2806,7 +2915,7 @@ numeric_stddev_pop(PG_FUNCTION_ARGS)
 	Numeric		res;
 	bool		is_null;
 
-	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
+	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
 								  false, false, &is_null);
 
 	if (is_null)
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index f40961f..ff71eca 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -11402,12 +11402,14 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 	int			i_aggfinalfn;
 	int			i_aggsortop;
 	int			i_aggtranstype;
+	int 		i_aggtransspace;
 	int			i_agginitval;
 	int			i_convertok;
 	const char *aggtransfn;
 	const char *aggfinalfn;
 	const char *aggsortop;
 	const char *aggtranstype;
+	const char *aggtransspace;
 	const char *agginitval;
 	bool		convertok;
 
@@ -11425,12 +11427,24 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 	selectSourceSchema(fout, agginfo->aggfn.dobj.namespace->dobj.name);
 
 	/* Get aggregate-specific details */
-	if (fout->remoteVersion >= 80100)
+	if (fout->remoteVersion >= 90300)
+	{
+		appendPQExpBuffer(query, "SELECT aggtransfn, "
+						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
+						  "aggsortop::pg_catalog.regoperator, "
+						  "aggtransspace, agginitval, "
+						  "'t'::boolean AS convertok "
+					  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
+						  "WHERE a.aggfnoid = p.oid "
+						  "AND p.oid = '%u'::pg_catalog.oid",
+						  agginfo->aggfn.dobj.catId.oid);
+	}
+	else if (fout->remoteVersion >= 80100)
 	{
 		appendPQExpBuffer(query, "SELECT aggtransfn, "
 						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
 						  "aggsortop::pg_catalog.regoperator, "
-						  "agginitval, "
+						  "0 AS aggtransspace, agginitval, "
 						  "'t'::boolean AS convertok "
 					  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
 						  "WHERE a.aggfnoid = p.oid "
@@ -11442,7 +11456,7 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 		appendPQExpBuffer(query, "SELECT aggtransfn, "
 						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
 						  "0 AS aggsortop, "
-						  "agginitval, "
+						  "0 AS aggtransspace, agginitval, "
 						  "'t'::boolean AS convertok "
 					  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
 						  "WHERE a.aggfnoid = p.oid "
@@ -11454,7 +11468,7 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 		appendPQExpBuffer(query, "SELECT aggtransfn, aggfinalfn, "
 						  "format_type(aggtranstype, NULL) AS aggtranstype, "
 						  "0 AS aggsortop, "
-						  "agginitval, "
+						  "0 AS aggtransspace, agginitval, "
 						  "'t'::boolean AS convertok "
 						  "FROM pg_aggregate "
 						  "WHERE oid = '%u'::oid",
@@ -11466,7 +11480,7 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 						  "aggfinalfn, "
 						  "(SELECT typname FROM pg_type WHERE oid = aggtranstype1) AS aggtranstype, "
 						  "0 AS aggsortop, "
-						  "agginitval1 AS agginitval, "
+						  "0 AS aggtransspace, agginitval1 AS agginitval, "
 						  "(aggtransfn2 = 0 and aggtranstype2 = 0 and agginitval2 is null) AS convertok "
 						  "FROM pg_aggregate "
 						  "WHERE oid = '%u'::oid",
@@ -11479,6 +11493,7 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 	i_aggfinalfn = PQfnumber(res, "aggfinalfn");
 	i_aggsortop = PQfnumber(res, "aggsortop");
 	i_aggtranstype = PQfnumber(res, "aggtranstype");
+	i_aggtransspace = PQfnumber(res, "aggtransspace");
 	i_agginitval = PQfnumber(res, "agginitval");
 	i_convertok = PQfnumber(res, "convertok");
 
@@ -11486,6 +11501,7 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 	aggfinalfn = PQgetvalue(res, 0, i_aggfinalfn);
 	aggsortop = PQgetvalue(res, 0, i_aggsortop);
 	aggtranstype = PQgetvalue(res, 0, i_aggtranstype);
+	aggtransspace = PQgetvalue(res, 0, i_aggtransspace);
 	agginitval = PQgetvalue(res, 0, i_agginitval);
 	convertok = (PQgetvalue(res, 0, i_convertok)[0] == 't');
 
@@ -11522,6 +11538,12 @@ dumpAgg(Archive *fout, AggInfo *agginfo)
 						  fmtId(aggtranstype));
 	}
 
+	if (strcmp(aggtransspace, "0") != 0)
+	{
+		appendPQExpBuffer(details, ",\n    SSPACE = %s",
+						  aggtransspace);
+	}
+
 	if (!PQgetisnull(res, 0, i_agginitval))
 	{
 		appendPQExpBuffer(details, ",\n    INITCOND = ");
diff --git a/src/include/catalog/pg_aggregate.h b/src/include/catalog/pg_aggregate.h
index 6fb10a9..385c906 100644
--- a/src/include/catalog/pg_aggregate.h
+++ b/src/include/catalog/pg_aggregate.h
@@ -44,6 +44,7 @@ CATALOG(pg_aggregate,2600) BKI_WITHOUT_OIDS
 	regproc		aggfinalfn;
 	Oid			aggsortop;
 	Oid			aggtranstype;
+	int32		aggtransspace;
 
 #ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	text		agginitval;
@@ -62,13 +63,14 @@ typedef FormData_pg_aggregate *Form_pg_aggregate;
  * ----------------
  */
 
-#define Natts_pg_aggregate				6
+#define Natts_pg_aggregate				7
 #define Anum_pg_aggregate_aggfnoid		1
 #define Anum_pg_aggregate_aggtransfn	2
 #define Anum_pg_aggregate_aggfinalfn	3
 #define Anum_pg_aggregate_aggsortop		4
 #define Anum_pg_aggregate_aggtranstype	5
-#define Anum_pg_aggregate_agginitval	6
+#define Anum_pg_aggregate_aggtransspace	6
+#define Anum_pg_aggregate_agginitval	7
 
 
 /* ----------------
@@ -77,163 +79,163 @@ typedef FormData_pg_aggregate *Form_pg_aggregate;
  */
 
 /* avg */
-DATA(insert ( 2100	int8_avg_accum	numeric_avg		0	1231	"{0,0}" ));
-DATA(insert ( 2101	int4_avg_accum	int8_avg		0	1016	"{0,0}" ));
-DATA(insert ( 2102	int2_avg_accum	int8_avg		0	1016	"{0,0}" ));
-DATA(insert ( 2103	numeric_avg_accum	numeric_avg		0	1231	"{0,0}" ));
-DATA(insert ( 2104	float4_accum	float8_avg		0	1022	"{0,0,0}" ));
-DATA(insert ( 2105	float8_accum	float8_avg		0	1022	"{0,0,0}" ));
-DATA(insert ( 2106	interval_accum	interval_avg	0	1187	"{0 second,0 second}" ));
+DATA(insert ( 2100	int8_avg_accum		numeric_avg		0	2281	128	_null_ ));
+DATA(insert ( 2101	int4_avg_accum		int8_avg		0	1016	0	"{0,0}" ));
+DATA(insert ( 2102	int2_avg_accum		int8_avg		0	1016	0	"{0,0}" ));
+DATA(insert ( 2103	numeric_accum		numeric_avg		0	2281	128	_null_ ));
+DATA(insert ( 2104	float4_accum		float8_avg		0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2105	float8_accum		float8_avg		0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2106	interval_accum		interval_avg	0	1187	0	"{0 second,0 second}" ));
 
 /* sum */
-DATA(insert ( 2107	int8_sum		-				0	1700	_null_ ));
-DATA(insert ( 2108	int4_sum		-				0	20		_null_ ));
-DATA(insert ( 2109	int2_sum		-				0	20		_null_ ));
-DATA(insert ( 2110	float4pl		-				0	700		_null_ ));
-DATA(insert ( 2111	float8pl		-				0	701		_null_ ));
-DATA(insert ( 2112	cash_pl			-				0	790		_null_ ));
-DATA(insert ( 2113	interval_pl		-				0	1186	_null_ ));
-DATA(insert ( 2114	numeric_add		-				0	1700	_null_ ));
+DATA(insert ( 2107	int8_avg_accum	numeric_sum		0	2281	128	_null_ ));
+DATA(insert ( 2108	int4_sum		-				0	20		0	_null_ ));
+DATA(insert ( 2109	int2_sum		-				0	20		0	_null_ ));
+DATA(insert ( 2110	float4pl		-				0	700		0	_null_ ));
+DATA(insert ( 2111	float8pl		-				0	701		0	_null_ ));
+DATA(insert ( 2112	cash_pl			-				0	790		0	_null_ ));
+DATA(insert ( 2113	interval_pl		-				0	1186	0	_null_ ));
+DATA(insert ( 2114	numeric_avg_accum	numeric_sum	0	2281	128	_null_ ));
 
 /* max */
-DATA(insert ( 2115	int8larger		-				413		20		_null_ ));
-DATA(insert ( 2116	int4larger		-				521		23		_null_ ));
-DATA(insert ( 2117	int2larger		-				520		21		_null_ ));
-DATA(insert ( 2118	oidlarger		-				610		26		_null_ ));
-DATA(insert ( 2119	float4larger	-				623		700		_null_ ));
-DATA(insert ( 2120	float8larger	-				674		701		_null_ ));
-DATA(insert ( 2121	int4larger		-				563		702		_null_ ));
-DATA(insert ( 2122	date_larger		-				1097	1082	_null_ ));
-DATA(insert ( 2123	time_larger		-				1112	1083	_null_ ));
-DATA(insert ( 2124	timetz_larger	-				1554	1266	_null_ ));
-DATA(insert ( 2125	cashlarger		-				903		790		_null_ ));
-DATA(insert ( 2126	timestamp_larger	-			2064	1114	_null_ ));
-DATA(insert ( 2127	timestamptz_larger	-			1324	1184	_null_ ));
-DATA(insert ( 2128	interval_larger -				1334	1186	_null_ ));
-DATA(insert ( 2129	text_larger		-				666		25		_null_ ));
-DATA(insert ( 2130	numeric_larger	-				1756	1700	_null_ ));
-DATA(insert ( 2050	array_larger	-				1073	2277	_null_ ));
-DATA(insert ( 2244	bpchar_larger	-				1060	1042	_null_ ));
-DATA(insert ( 2797	tidlarger		-				2800	27		_null_ ));
-DATA(insert ( 3526	enum_larger		-				3519	3500	_null_ ));
+DATA(insert ( 2115	int8larger		-				413		20		0	_null_ ));
+DATA(insert ( 2116	int4larger		-				521		23		0	_null_ ));
+DATA(insert ( 2117	int2larger		-				520		21		0	_null_ ));
+DATA(insert ( 2118	oidlarger		-				610		26		0	_null_ ));
+DATA(insert ( 2119	float4larger	-				623		700		0	_null_ ));
+DATA(insert ( 2120	float8larger	-				674		701		0	_null_ ));
+DATA(insert ( 2121	int4larger		-				563		702		0	_null_ ));
+DATA(insert ( 2122	date_larger		-				1097	1082	0	_null_ ));
+DATA(insert ( 2123	time_larger		-				1112	1083	0	_null_ ));
+DATA(insert ( 2124	timetz_larger	-				1554	1266	0	_null_ ));
+DATA(insert ( 2125	cashlarger		-				903		790		0	_null_ ));
+DATA(insert ( 2126	timestamp_larger	-			2064	1114	0	_null_ ));
+DATA(insert ( 2127	timestamptz_larger	-			1324	1184	0	_null_ ));
+DATA(insert ( 2128	interval_larger -				1334	1186	0	_null_ ));
+DATA(insert ( 2129	text_larger		-				666		25		0	_null_ ));
+DATA(insert ( 2130	numeric_larger	-				1756	1700	0	_null_ ));
+DATA(insert ( 2050	array_larger	-				1073	2277	0	_null_ ));
+DATA(insert ( 2244	bpchar_larger	-				1060	1042	0	_null_ ));
+DATA(insert ( 2797	tidlarger		-				2800	27		0	_null_ ));
+DATA(insert ( 3526	enum_larger		-				3519	3500	0	_null_ ));
 
 /* min */
-DATA(insert ( 2131	int8smaller		-				412		20		_null_ ));
-DATA(insert ( 2132	int4smaller		-				97		23		_null_ ));
-DATA(insert ( 2133	int2smaller		-				95		21		_null_ ));
-DATA(insert ( 2134	oidsmaller		-				609		26		_null_ ));
-DATA(insert ( 2135	float4smaller	-				622		700		_null_ ));
-DATA(insert ( 2136	float8smaller	-				672		701		_null_ ));
-DATA(insert ( 2137	int4smaller		-				562		702		_null_ ));
-DATA(insert ( 2138	date_smaller	-				1095	1082	_null_ ));
-DATA(insert ( 2139	time_smaller	-				1110	1083	_null_ ));
-DATA(insert ( 2140	timetz_smaller	-				1552	1266	_null_ ));
-DATA(insert ( 2141	cashsmaller		-				902		790		_null_ ));
-DATA(insert ( 2142	timestamp_smaller	-			2062	1114	_null_ ));
-DATA(insert ( 2143	timestamptz_smaller -			1322	1184	_null_ ));
-DATA(insert ( 2144	interval_smaller	-			1332	1186	_null_ ));
-DATA(insert ( 2145	text_smaller	-				664		25		_null_ ));
-DATA(insert ( 2146	numeric_smaller -				1754	1700	_null_ ));
-DATA(insert ( 2051	array_smaller	-				1072	2277	_null_ ));
-DATA(insert ( 2245	bpchar_smaller	-				1058	1042	_null_ ));
-DATA(insert ( 2798	tidsmaller		-				2799	27		_null_ ));
-DATA(insert ( 3527	enum_smaller	-				3518	3500	_null_ ));
+DATA(insert ( 2131	int8smaller		-				412		20		0	_null_ ));
+DATA(insert ( 2132	int4smaller		-				97		23		0	_null_ ));
+DATA(insert ( 2133	int2smaller		-				95		21		0	_null_ ));
+DATA(insert ( 2134	oidsmaller		-				609		26		0	_null_ ));
+DATA(insert ( 2135	float4smaller	-				622		700		0	_null_ ));
+DATA(insert ( 2136	float8smaller	-				672		701		0	_null_ ));
+DATA(insert ( 2137	int4smaller		-				562		702		0	_null_ ));
+DATA(insert ( 2138	date_smaller	-				1095	1082	0	_null_ ));
+DATA(insert ( 2139	time_smaller	-				1110	1083	0	_null_ ));
+DATA(insert ( 2140	timetz_smaller	-				1552	1266	0	_null_ ));
+DATA(insert ( 2141	cashsmaller		-				902		790		0	_null_ ));
+DATA(insert ( 2142	timestamp_smaller	-			2062	1114	0	_null_ ));
+DATA(insert ( 2143	timestamptz_smaller -			1322	1184	0	_null_ ));
+DATA(insert ( 2144	interval_smaller	-			1332	1186	0	_null_ ));
+DATA(insert ( 2145	text_smaller	-				664		25		0	_null_ ));
+DATA(insert ( 2146	numeric_smaller -				1754	1700	0	_null_ ));
+DATA(insert ( 2051	array_smaller	-				1072	2277	0	_null_ ));
+DATA(insert ( 2245	bpchar_smaller	-				1058	1042	0	_null_ ));
+DATA(insert ( 2798	tidsmaller		-				2799	27		0	_null_ ));
+DATA(insert ( 3527	enum_smaller	-				3518	3500	0	_null_ ));
 
 /* count */
-DATA(insert ( 2147	int8inc_any		-				0		20		"0" ));
-DATA(insert ( 2803	int8inc			-				0		20		"0" ));
+DATA(insert ( 2147	int8inc_any		-				0		20		0	"0" ));
+DATA(insert ( 2803	int8inc			-				0		20		0	"0" ));
 
 /* var_pop */
-DATA(insert ( 2718	int8_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
-DATA(insert ( 2719	int4_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
-DATA(insert ( 2720	int2_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
-DATA(insert ( 2721	float4_accum	float8_var_pop 0	1022	"{0,0,0}" ));
-DATA(insert ( 2722	float8_accum	float8_var_pop 0	1022	"{0,0,0}" ));
-DATA(insert ( 2723	numeric_accum  numeric_var_pop 0	1231	"{0,0,0}" ));
+DATA(insert ( 2718	int8_accum	numeric_var_pop 0	2281	128	_null_ ));
+DATA(insert ( 2719	int4_accum	numeric_var_pop 0	2281	128	_null_ ));
+DATA(insert ( 2720	int2_accum	numeric_var_pop 0	2281	128	_null_ ));
+DATA(insert ( 2721	float4_accum	float8_var_pop 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2722	float8_accum	float8_var_pop 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2723	numeric_accum  numeric_var_pop 0	2281	128	_null_ ));
 
 /* var_samp */
-DATA(insert ( 2641	int8_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2642	int4_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2643	int2_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2644	float4_accum	float8_var_samp 0	1022	"{0,0,0}" ));
-DATA(insert ( 2645	float8_accum	float8_var_samp 0	1022	"{0,0,0}" ));
-DATA(insert ( 2646	numeric_accum  numeric_var_samp 0	1231	"{0,0,0}" ));
+DATA(insert ( 2641	int8_accum	numeric_var_samp	0	2281	128	_null_ ));
+DATA(insert ( 2642	int4_accum	numeric_var_samp	0	2281	128	_null_ ));
+DATA(insert ( 2643	int2_accum	numeric_var_samp	0	2281	128	_null_ ));
+DATA(insert ( 2644	float4_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2645	float8_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2646	numeric_accum  numeric_var_samp 0	2281	128	_null_ ));
 
 /* variance: historical Postgres syntax for var_samp */
-DATA(insert ( 2148	int8_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2149	int4_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2150	int2_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
-DATA(insert ( 2151	float4_accum	float8_var_samp 0	1022	"{0,0,0}" ));
-DATA(insert ( 2152	float8_accum	float8_var_samp 0	1022	"{0,0,0}" ));
-DATA(insert ( 2153	numeric_accum  numeric_var_samp 0	1231	"{0,0,0}" ));
+DATA(insert ( 2148	int8_accum	numeric_var_samp	0	2281	128	_null_ ));
+DATA(insert ( 2149	int4_accum	numeric_var_samp	0	2281	128	_null_ ));
+DATA(insert ( 2150	int2_accum	numeric_var_samp	0	2281	128	_null_ ));
+DATA(insert ( 2151	float4_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2152	float8_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2153	numeric_accum  numeric_var_samp 0	2281	128	_null_ ));
 
 /* stddev_pop */
-DATA(insert ( 2724	int8_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
-DATA(insert ( 2725	int4_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
-DATA(insert ( 2726	int2_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
-DATA(insert ( 2727	float4_accum	float8_stddev_pop	0	1022	"{0,0,0}" ));
-DATA(insert ( 2728	float8_accum	float8_stddev_pop	0	1022	"{0,0,0}" ));
-DATA(insert ( 2729	numeric_accum	numeric_stddev_pop	0	1231	"{0,0,0}" ));
+DATA(insert ( 2724	int8_accum	numeric_stddev_pop		0	2281	128	_null_ ));
+DATA(insert ( 2725	int4_accum	numeric_stddev_pop		0	2281	128	_null_ ));
+DATA(insert ( 2726	int2_accum	numeric_stddev_pop		0	2281	128	_null_ ));
+DATA(insert ( 2727	float4_accum	float8_stddev_pop	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2728	float8_accum	float8_stddev_pop	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2729	numeric_accum	numeric_stddev_pop	0	2281	128	_null_ ));
 
 /* stddev_samp */
-DATA(insert ( 2712	int8_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2713	int4_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2714	int2_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2715	float4_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
-DATA(insert ( 2716	float8_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
-DATA(insert ( 2717	numeric_accum	numeric_stddev_samp 0	1231	"{0,0,0}" ));
+DATA(insert ( 2712	int8_accum	numeric_stddev_samp		0	2281	128	_null_ ));
+DATA(insert ( 2713	int4_accum	numeric_stddev_samp		0	2281	128	_null_ ));
+DATA(insert ( 2714	int2_accum	numeric_stddev_samp		0	2281	128	_null_ ));
+DATA(insert ( 2715	float4_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2716	float8_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2717	numeric_accum	numeric_stddev_samp 0	2281	128	_null_ ));
 
 /* stddev: historical Postgres syntax for stddev_samp */
-DATA(insert ( 2154	int8_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2155	int4_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2156	int2_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
-DATA(insert ( 2157	float4_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
-DATA(insert ( 2158	float8_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
-DATA(insert ( 2159	numeric_accum	numeric_stddev_samp 0	1231	"{0,0,0}" ));
+DATA(insert ( 2154	int8_accum	numeric_stddev_samp		0	2281	128	_null_ ));
+DATA(insert ( 2155	int4_accum	numeric_stddev_samp		0	2281	128	_null_ ));
+DATA(insert ( 2156	int2_accum	numeric_stddev_samp		0	2281	128	_null_ ));
+DATA(insert ( 2157	float4_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2158	float8_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2159	numeric_accum	numeric_stddev_samp 0	2281	128	_null_ ));
 
 /* SQL2003 binary regression aggregates */
-DATA(insert ( 2818	int8inc_float8_float8		-				0	20		"0" ));
-DATA(insert ( 2819	float8_regr_accum	float8_regr_sxx			0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2820	float8_regr_accum	float8_regr_syy			0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2821	float8_regr_accum	float8_regr_sxy			0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2822	float8_regr_accum	float8_regr_avgx		0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2823	float8_regr_accum	float8_regr_avgy		0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2824	float8_regr_accum	float8_regr_r2			0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2825	float8_regr_accum	float8_regr_slope		0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2826	float8_regr_accum	float8_regr_intercept	0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2827	float8_regr_accum	float8_covar_pop		0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2828	float8_regr_accum	float8_covar_samp		0	1022	"{0,0,0,0,0,0}" ));
-DATA(insert ( 2829	float8_regr_accum	float8_corr				0	1022	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2818	int8inc_float8_float8		-				0	20		0	"0" ));
+DATA(insert ( 2819	float8_regr_accum	float8_regr_sxx			0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2820	float8_regr_accum	float8_regr_syy			0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2821	float8_regr_accum	float8_regr_sxy			0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2822	float8_regr_accum	float8_regr_avgx		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2823	float8_regr_accum	float8_regr_avgy		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2824	float8_regr_accum	float8_regr_r2			0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2825	float8_regr_accum	float8_regr_slope		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2826	float8_regr_accum	float8_regr_intercept	0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2827	float8_regr_accum	float8_covar_pop		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2828	float8_regr_accum	float8_covar_samp		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2829	float8_regr_accum	float8_corr				0	1022	0	"{0,0,0,0,0,0}" ));
 
 /* boolean-and and boolean-or */
-DATA(insert ( 2517	booland_statefunc	-			58	16		_null_ ));
-DATA(insert ( 2518	boolor_statefunc	-			59	16		_null_ ));
-DATA(insert ( 2519	booland_statefunc	-			58	16		_null_ ));
+DATA(insert ( 2517	booland_statefunc	-			58	16		0	_null_ ));
+DATA(insert ( 2518	boolor_statefunc	-			59	16		0	_null_ ));
+DATA(insert ( 2519	booland_statefunc	-			58	16		0	_null_ ));
 
 /* bitwise integer */
-DATA(insert ( 2236 int2and		  -					0	21		_null_ ));
-DATA(insert ( 2237 int2or		  -					0	21		_null_ ));
-DATA(insert ( 2238 int4and		  -					0	23		_null_ ));
-DATA(insert ( 2239 int4or		  -					0	23		_null_ ));
-DATA(insert ( 2240 int8and		  -					0	20		_null_ ));
-DATA(insert ( 2241 int8or		  -					0	20		_null_ ));
-DATA(insert ( 2242 bitand		  -					0	1560	_null_ ));
-DATA(insert ( 2243 bitor		  -					0	1560	_null_ ));
+DATA(insert ( 2236 int2and		  -					0	21		0	_null_ ));
+DATA(insert ( 2237 int2or		  -					0	21		0	_null_ ));
+DATA(insert ( 2238 int4and		  -					0	23		0	_null_ ));
+DATA(insert ( 2239 int4or		  -					0	23		0	_null_ ));
+DATA(insert ( 2240 int8and		  -					0	20		0	_null_ ));
+DATA(insert ( 2241 int8or		  -					0	20		0	_null_ ));
+DATA(insert ( 2242 bitand		  -					0	1560	0	_null_ ));
+DATA(insert ( 2243 bitor		  -					0	1560	0	_null_ ));
 
 /* xml */
-DATA(insert ( 2901 xmlconcat2	  -					0	142		_null_ ));
+DATA(insert ( 2901 xmlconcat2	  -					0	142		0	_null_ ));
 
 /* array */
-DATA(insert ( 2335	array_agg_transfn	array_agg_finalfn		0	2281	_null_ ));
+DATA(insert ( 2335	array_agg_transfn	array_agg_finalfn		0	2281	0	_null_ ));
 
 /* text */
-DATA(insert ( 3538	string_agg_transfn	string_agg_finalfn		0	2281	_null_ ));
+DATA(insert ( 3538	string_agg_transfn	string_agg_finalfn		0	2281	0	_null_ ));
 
 /* bytea */
-DATA(insert ( 3545	bytea_string_agg_transfn	bytea_string_agg_finalfn		0	2281	_null_ ));
+DATA(insert ( 3545	bytea_string_agg_transfn	bytea_string_agg_finalfn		0	2281	0	_null_ ));
 
 /* json */
-DATA(insert ( 3175	json_agg_transfn	json_agg_finalfn		0	2281	_null_ ));
+DATA(insert ( 3175	json_agg_transfn	json_agg_finalfn		0	2281	0	_null_ ));
 
 /*
  * prototypes for functions in pg_aggregate.c
@@ -246,6 +248,7 @@ extern Oid AggregateCreate(const char *aggName,
 				List *aggfinalfnName,
 				List *aggsortopName,
 				Oid aggTransType,
+				int32 aggTransSpace,
 				const char *agginitval);
 
 #endif   /* PG_AGGREGATE_H */
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 90aff3d..b413e60 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2381,27 +2381,29 @@ DATA(insert OID = 2513 (  float8_stddev_pop PGNSP PGUID 12 1 0 0 0 f f f f t f i
 DESCR("aggregate final function");
 DATA(insert OID = 1832 (  float8_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 701 "1022" _null_ _null_ _null_ _null_ float8_stddev_samp _null_ _null_ _null_ ));
 DESCR("aggregate final function");
-DATA(insert OID = 1833 (  numeric_accum    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 1700" _null_ _null_ _null_ _null_ numeric_accum _null_ _null_ _null_ ));
+DATA(insert OID = 1833 (  numeric_accum    PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 1700" _null_ _null_ _null_ _null_ numeric_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 2858 (  numeric_avg_accum    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 1700" _null_ _null_ _null_ _null_ numeric_avg_accum _null_ _null_ _null_ ));
+DATA(insert OID = 2858 (  numeric_avg_accum    PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 1700" _null_ _null_ _null_ _null_ numeric_avg_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 1834 (  int2_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 21" _null_ _null_ _null_ _null_ int2_accum _null_ _null_ _null_ ));
+DATA(insert OID = 1834 (  int2_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 21" _null_ _null_ _null_ _null_ int2_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 1835 (  int4_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 23" _null_ _null_ _null_ _null_ int4_accum _null_ _null_ _null_ ));
+DATA(insert OID = 1835 (  int4_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 23" _null_ _null_ _null_ _null_ int4_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 1836 (  int8_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 20" _null_ _null_ _null_ _null_ int8_accum _null_ _null_ _null_ ));
+DATA(insert OID = 1836 (  int8_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 20" _null_ _null_ _null_ _null_ int8_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 2746 (  int8_avg_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 20" _null_ _null_ _null_ _null_ int8_avg_accum _null_ _null_ _null_ ));
+DATA(insert OID = 2746 (  int8_avg_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 20" _null_ _null_ _null_ _null_ int8_avg_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
-DATA(insert OID = 1837 (  numeric_avg	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_avg _null_ _null_ _null_ ));
+DATA(insert OID = 1837 (  numeric_avg	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_avg _null_ _null_ _null_ ));
 DESCR("aggregate final function");
-DATA(insert OID = 2514 (  numeric_var_pop  PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_var_pop _null_ _null_ _null_ ));
+DATA(insert OID = 3179 (  numeric_sum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_sum _null_ _null_ _null_ ));
 DESCR("aggregate final function");
-DATA(insert OID = 1838 (  numeric_var_samp PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_var_samp _null_ _null_ _null_ ));
+DATA(insert OID = 2514 (  numeric_var_pop  PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_var_pop _null_ _null_ _null_ ));
 DESCR("aggregate final function");
-DATA(insert OID = 2596 (  numeric_stddev_pop PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_	numeric_stddev_pop _null_ _null_ _null_ ));
+DATA(insert OID = 1838 (  numeric_var_samp PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_var_samp _null_ _null_ _null_ ));
 DESCR("aggregate final function");
-DATA(insert OID = 1839 (  numeric_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_stddev_samp _null_ _null_ _null_ ));
+DATA(insert OID = 2596 (  numeric_stddev_pop PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_	numeric_stddev_pop _null_ _null_ _null_ ));
+DESCR("aggregate final function");
+DATA(insert OID = 1839 (  numeric_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_stddev_samp _null_ _null_ _null_ ));
 DESCR("aggregate final function");
 DATA(insert OID = 1840 (  int2_sum		   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 20 "20 21" _null_ _null_ _null_ _null_ int2_sum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index fa9f41f..7ccb656 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -122,6 +122,7 @@ extern Datum transformGenericOptions(Oid catalogId,
 extern char *defGetString(DefElem *def);
 extern double defGetNumeric(DefElem *def);
 extern bool defGetBoolean(DefElem *def);
+extern int32 defGetInt32(DefElem *def);
 extern int64 defGetInt64(DefElem *def);
 extern List *defGetQualifiedName(DefElem *def);
 extern TypeName *defGetTypeName(DefElem *def);
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 667c58b..9e3ef1c 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -981,6 +981,7 @@ extern Datum int4_accum(PG_FUNCTION_ARGS);
 extern Datum int8_accum(PG_FUNCTION_ARGS);
 extern Datum int8_avg_accum(PG_FUNCTION_ARGS);
 extern Datum numeric_avg(PG_FUNCTION_ARGS);
+extern Datum numeric_sum(PG_FUNCTION_ARGS);
 extern Datum numeric_var_pop(PG_FUNCTION_ARGS);
 extern Datum numeric_var_samp(PG_FUNCTION_ARGS);
 extern Datum numeric_stddev_pop(PG_FUNCTION_ARGS);

*** a/doc/src/sgml/catalogs.sgml
--- b/doc/src/sgml/catalogs.sgml
***************
*** 373,378 ****
--- 373,384 ----
        <entry>Data type of the aggregate function's internal transition (state) data</entry>
       </row>
       <row>
+       <entry><structfield>aggtransspace</structfield></entry>
+       <entry><type>int4</type></entry>
+       <entry></entry>
+       <entry>Approximation for the average size of the aggregate function's internal transition (state) data</entry>
+      </row>
+      <row>
        <entry><structfield>agginitval</structfield></entry>
        <entry><type>text</type></entry>
        <entry></entry>
*** a/doc/src/sgml/ref/create_aggregate.sgml
--- b/doc/src/sgml/ref/create_aggregate.sgml
***************
*** 24,29 **** PostgreSQL documentation
--- 24,30 ----
  CREATE AGGREGATE <replaceable class="PARAMETER">name</replaceable> ( <replaceable class="PARAMETER">input_data_type</replaceable> [ , ... ] ) (
      SFUNC = <replaceable class="PARAMETER">sfunc</replaceable>,
      STYPE = <replaceable class="PARAMETER">state_data_type</replaceable>
+     [ , SSPACE = <replaceable class="PARAMETER">state_data_size</replaceable> ]
      [ , FINALFUNC = <replaceable class="PARAMETER">ffunc</replaceable> ]
      [ , INITCOND = <replaceable class="PARAMETER">initial_condition</replaceable> ]
      [ , SORTOP = <replaceable class="PARAMETER">sort_operator</replaceable> ]
***************
*** 35,40 **** CREATE AGGREGATE <replaceable class="PARAMETER">name</replaceable> (
--- 36,42 ----
      BASETYPE = <replaceable class="PARAMETER">base_type</replaceable>,
      SFUNC = <replaceable class="PARAMETER">sfunc</replaceable>,
      STYPE = <replaceable class="PARAMETER">state_data_type</replaceable>
+     [ , SSPACE = <replaceable class="PARAMETER">state_data_size</replaceable> ]
      [ , FINALFUNC = <replaceable class="PARAMETER">ffunc</replaceable> ]
      [ , INITCOND = <replaceable class="PARAMETER">initial_condition</replaceable> ]
      [ , SORTOP = <replaceable class="PARAMETER">sort_operator</replaceable> ]
***************
*** 241,246 **** SELECT col FROM tab ORDER BY col USING sortop LIMIT 1;
--- 243,260 ----
     </varlistentry>
  
     <varlistentry>
+     <term><replaceable class="PARAMETER">state_data_size</replaceable></term>
+     <listitem>
+      <para>
+       Approximate average size (in bytes) of aggregate's state value. 
+       Planner uses this value to approximate the memory required for 
+       the aggregation. If this value is not provided, a default value is 
+       used based on state_data_type.
+      </para>
+     </listitem>
+    </varlistentry>
+ 
+    <varlistentry>
      <term><replaceable class="PARAMETER">ffunc</replaceable></term>
      <listitem>
       <para>
*** a/src/backend/catalog/pg_aggregate.c
--- b/src/backend/catalog/pg_aggregate.c
***************
*** 51,56 **** AggregateCreate(const char *aggName,
--- 51,57 ----
  				List *aggfinalfnName,
  				List *aggsortopName,
  				Oid aggTransType,
+ 				int32 aggTransSpace,
  				const char *agginitval)
  {
  	Relation	aggdesc;
***************
*** 269,274 **** AggregateCreate(const char *aggName,
--- 270,276 ----
  	values[Anum_pg_aggregate_aggfinalfn - 1] = ObjectIdGetDatum(finalfn);
  	values[Anum_pg_aggregate_aggsortop - 1] = ObjectIdGetDatum(sortop);
  	values[Anum_pg_aggregate_aggtranstype - 1] = ObjectIdGetDatum(aggTransType);
+ 	values[Anum_pg_aggregate_aggtransspace - 1] = Int32GetDatum(aggTransSpace);
  	if (agginitval)
  		values[Anum_pg_aggregate_agginitval - 1] = CStringGetTextDatum(agginitval);
  	else
*** a/src/backend/commands/aggregatecmds.c
--- b/src/backend/commands/aggregatecmds.c
***************
*** 62,67 **** DefineAggregate(List *name, List *args, bool oldstyle, List *parameters)
--- 62,68 ----
  	Oid		   *aggArgTypes;
  	int			numArgs;
  	Oid			transTypeId;
+ 	int32		transSpace = 0;
  	char		transTypeType;
  	ListCell   *pl;
  
***************
*** 96,101 **** DefineAggregate(List *name, List *args, bool oldstyle, List *parameters)
--- 97,104 ----
  			transType = defGetTypeName(defel);
  		else if (pg_strcasecmp(defel->defname, "stype1") == 0)
  			transType = defGetTypeName(defel);
+ 		else if (pg_strcasecmp(defel->defname, "sspace") == 0)
+ 			transSpace = defGetInt32(defel);
  		else if (pg_strcasecmp(defel->defname, "initcond") == 0)
  			initval = defGetString(defel);
  		else if (pg_strcasecmp(defel->defname, "initcond1") == 0)
***************
*** 225,229 **** DefineAggregate(List *name, List *args, bool oldstyle, List *parameters)
--- 228,233 ----
  						   finalfuncName,		/* final function name */
  						   sortoperatorName,	/* sort operator name */
  						   transTypeId, /* transition data type */
+ 						   transSpace,			/* transition space */
  						   initval);	/* initial condition */
  }
*** a/src/backend/commands/define.c
--- b/src/backend/commands/define.c
***************
*** 165,170 **** defGetBoolean(DefElem *def)
--- 165,194 ----
  }
  
  /*
+  * Extract an int32 value from a DefElem.
+  */
+ int32
+ defGetInt32(DefElem *def)
+ {
+ 	if (def->arg == NULL)
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_SYNTAX_ERROR),
+ 				 errmsg("%s requires an integer value",
+ 						def->defname)));
+ 	switch (nodeTag(def->arg))
+ 	{
+ 		case T_Integer:
+ 			return (int32) intVal(def->arg);
+ 		default:
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_SYNTAX_ERROR),
+ 					 errmsg("%s requires an integer value",
+ 							def->defname)));
+ 	}
+ 	return 0;					/* keep compiler quiet */
+ }
+ 
+ /*
   * Extract an int64 value from a DefElem.
   */
  int64
*** a/src/backend/optimizer/util/clauses.c
--- b/src/backend/optimizer/util/clauses.c
***************
*** 461,466 **** count_agg_clauses_walker(Node *node, count_agg_clauses_context *context)
--- 461,467 ----
  		Oid			aggtransfn;
  		Oid			aggfinalfn;
  		Oid			aggtranstype;
+ 		int32 		aggtransspace;
  		QualCost	argcosts;
  		Oid		   *inputTypes;
  		int			numArguments;
***************
*** 478,483 **** count_agg_clauses_walker(Node *node, count_agg_clauses_context *context)
--- 479,485 ----
  		aggtransfn = aggform->aggtransfn;
  		aggfinalfn = aggform->aggfinalfn;
  		aggtranstype = aggform->aggtranstype;
+ 		aggtransspace = aggform->aggtransspace;
  		ReleaseSysCache(aggTuple);
  
  		/* count it */
***************
*** 524,536 **** count_agg_clauses_walker(Node *node, count_agg_clauses_context *context)
  			pfree(declaredArgTypes);
  		}
  
  		/*
  		 * If the transition type is pass-by-value then it doesn't add
  		 * anything to the required size of the hashtable.	If it is
  		 * pass-by-reference then we have to add the estimated size of the
  		 * value itself, plus palloc overhead.
  		 */
! 		if (!get_typbyval(aggtranstype))
  		{
  			int32		aggtranstypmod;
  			int32		avgwidth;
--- 526,546 ----
  			pfree(declaredArgTypes);
  		}
  
+ 		/* 
+ 		 * If approximate average space used by aggregate transition value is
+ 		 * specified in pg_aggregate, then use it for transitionSpace.
+ 		 */
+ 		if (aggtransspace > 0)
+ 		{
+ 			costs->transitionSpace += aggtransspace;
+ 		}
  		/*
  		 * If the transition type is pass-by-value then it doesn't add
  		 * anything to the required size of the hashtable.	If it is
  		 * pass-by-reference then we have to add the estimated size of the
  		 * value itself, plus palloc overhead.
  		 */
! 		else if (!get_typbyval(aggtranstype))
  		{
  			int32		aggtranstypmod;
  			int32		avgwidth;
*** a/src/backend/utils/adt/numeric.c
--- b/src/backend/utils/adt/numeric.c
***************
*** 2464,2571 **** numeric_float4(PG_FUNCTION_ARGS)
   *
   * Aggregate functions
   *
!  * The transition datatype for all these aggregates is a 3-element array
!  * of Numeric, holding the values N, sum(X), sum(X*X) in that order.
!  *
!  * We represent N as a numeric mainly to avoid having to build a special
!  * datatype; it's unlikely it'd overflow an int4, but ...
   *
   * ----------------------------------------------------------------------
   */
  
! static ArrayType *
! do_numeric_accum(ArrayType *transarray, Numeric newval)
  {
! 	Datum	   *transdatums;
! 	int			ndatums;
! 	Datum		N,
! 				sumX,
! 				sumX2;
! 	ArrayType  *result;
! 
! 	/* We assume the input is array of numeric */
! 	deconstruct_array(transarray,
! 					  NUMERICOID, -1, false, 'i',
! 					  &transdatums, NULL, &ndatums);
! 	if (ndatums != 3)
! 		elog(ERROR, "expected 3-element numeric array");
! 	N = transdatums[0];
! 	sumX = transdatums[1];
! 	sumX2 = transdatums[2];
! 
! 	N = DirectFunctionCall1(numeric_inc, N);
! 	sumX = DirectFunctionCall2(numeric_add, sumX,
! 							   NumericGetDatum(newval));
! 	sumX2 = DirectFunctionCall2(numeric_add, sumX2,
! 								DirectFunctionCall2(numeric_mul,
! 													NumericGetDatum(newval),
! 													NumericGetDatum(newval)));
! 
! 	transdatums[0] = N;
! 	transdatums[1] = sumX;
! 	transdatums[2] = sumX2;
! 
! 	result = construct_array(transdatums, 3,
! 							 NUMERICOID, -1, false, 'i');
  
! 	return result;
  }
  
! /*
!  * Improve avg performance by not caclulating sum(X*X).
!  */
! static ArrayType *
! do_numeric_avg_accum(ArrayType *transarray, Numeric newval)
  {
! 	Datum	   *transdatums;
! 	int			ndatums;
! 	Datum		N,
! 				sumX;
! 	ArrayType  *result;
! 
! 	/* We assume the input is array of numeric */
! 	deconstruct_array(transarray,
! 					  NUMERICOID, -1, false, 'i',
! 					  &transdatums, NULL, &ndatums);
! 	if (ndatums != 2)
! 		elog(ERROR, "expected 2-element numeric array");
! 	N = transdatums[0];
! 	sumX = transdatums[1];
! 
! 	N = DirectFunctionCall1(numeric_inc, N);
! 	sumX = DirectFunctionCall2(numeric_add, sumX,
! 							   NumericGetDatum(newval));
! 
! 	transdatums[0] = N;
! 	transdatums[1] = sumX;
! 
! 	result = construct_array(transdatums, 2,
! 							 NUMERICOID, -1, false, 'i');
  
! 	return result;
  }
  
  Datum
  numeric_accum(PG_FUNCTION_ARGS)
  {
! 	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
! 	Numeric		newval = PG_GETARG_NUMERIC(1);
  
! 	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
  }
  
  /*
   * Optimized case for average of numeric.
   */
  Datum
  numeric_avg_accum(PG_FUNCTION_ARGS)
  {
! 	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
! 	Numeric		newval = PG_GETARG_NUMERIC(1);
  
! 	PG_RETURN_ARRAYTYPE_P(do_numeric_avg_accum(transarray, newval));
  }
  
  /*
   * Integer data types all use Numeric accumulators to share code and
   * avoid risk of overflow.	For int2 and int4 inputs, Numeric accumulation
--- 2464,2620 ----
   *
   * Aggregate functions
   *
!  * The transition datatype for all these aggregates is a pointer to 
!  * a struct NumericAggState allocated in the aggregate context.
   *
   * ----------------------------------------------------------------------
   */
  
! typedef struct NumericAggState
! {
! 	bool 			first;
! 	bool 			isNaN;
! 	uint64			N;
! 	NumericVar 		sumX;
! 	NumericVar 		sumX2;
! 	bool 			calcSumX2;
! 	MemoryContext 	agg_context;
! } NumericAggState;
! 
! 
! static NumericAggState *
! makeNumericAggState(FunctionCallInfo fcinfo, bool calcSumX2)
  {
! 	NumericAggState 	*state;
! 	MemoryContext 		 agg_context;
! 	MemoryContext 		 old_context;
  
! 	if (!AggCheckCallContext(fcinfo, &agg_context))
! 	{
! 		elog(ERROR, "this is called in non-aggregate context");
! 	}
! 
! 	old_context = MemoryContextSwitchTo(agg_context);
! 
! 	state = palloc0(sizeof(NumericAggState));
! 	state->first = true;
! 	state->calcSumX2 = calcSumX2;
! 	state->agg_context = agg_context;
! 
! 	MemoryContextSwitchTo(old_context);
! 
! 	return state;
  }
  
! 
! static void
! do_numeric_accum(NumericAggState *state, Numeric newval)
  {
! 	NumericVar 		X;
! 	NumericVar 		X2;
! 	MemoryContext 	old_context;
! 	bool 			first;
! 	
! 	first = state->first;
! 	state->first = false;
! 	state->N++;
! 
! 	if (state->isNaN || NUMERIC_IS_NAN(newval))
! 	{
! 		state->isNaN = true;
! 		return;
! 	}
  
! 	init_var_from_num(newval, &X);
! 
! 	if (state->calcSumX2)
! 	{
! 		init_var(&X2);
! 		mul_var(&X, &X, &X2, X.dscale * 2);
! 	}
! 
! 	old_context = MemoryContextSwitchTo(state->agg_context);
! 
! 	if (!first)
! 	{
! 		NumericVar preSumX;
! 
! 		memcpy(&preSumX, &(state->sumX), sizeof(NumericVar));
! 		init_var(&(state->sumX));
! 		add_var(&X, &preSumX, &(state->sumX));
! 		free_var(&preSumX);
! 
! 		if (state->calcSumX2)
! 		{
! 			NumericVar preSumX2;
! 
! 			memcpy(&preSumX2, &(state->sumX2), sizeof(NumericVar));
! 			init_var(&(state->sumX2));
! 			add_var(&X2, &preSumX2, &(state->sumX2));
! 			free_var(&preSumX2);
! 		}
! 	}
! 	else
! 	{
! 		set_var_from_var(&X, &(state->sumX));
! 
! 		if (state->calcSumX2)
! 			set_var_from_var(&X2, &(state->sumX2));
! 	}
! 
! 	MemoryContextSwitchTo(old_context);
  }
  
+ 
  Datum
  numeric_accum(PG_FUNCTION_ARGS)
  {
! 	NumericAggState *state;
! 
! 	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
  
! 	if (!PG_ARGISNULL(1))
! 	{
! 		/* On the first time through, create the state variable. */
! 		if (state == NULL)
! 			state = makeNumericAggState(fcinfo, true);
! 		
! 		do_numeric_accum(state, PG_GETARG_NUMERIC(1));
! 	}
! 
! 	if (state == NULL)
! 		PG_RETURN_NULL();
! 	else
! 		PG_RETURN_POINTER(state);
  }
  
+ 
  /*
   * Optimized case for average of numeric.
   */
  Datum
  numeric_avg_accum(PG_FUNCTION_ARGS)
  {
! 	NumericAggState *state;
  
! 	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
! 
! 	if (!PG_ARGISNULL(1))
! 	{
! 		/* On the first time through, create the state variable. */
! 		if (state == NULL)
! 			state = makeNumericAggState(fcinfo, false);
! 		
! 		do_numeric_accum(state, PG_GETARG_NUMERIC(1));
! 	}
! 
! 	if (state == NULL)
! 		PG_RETURN_NULL();
! 	else
! 		PG_RETURN_POINTER(state);
  }
  
+ 
  /*
   * Integer data types all use Numeric accumulators to share code and
   * avoid risk of overflow.	For int2 and int4 inputs, Numeric accumulation
***************
*** 2578,2664 **** numeric_avg_accum(PG_FUNCTION_ARGS)
  Datum
  int2_accum(PG_FUNCTION_ARGS)
  {
! 	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
! 	Datum		newval2 = PG_GETARG_DATUM(1);
! 	Numeric		newval;
  
! 	newval = DatumGetNumeric(DirectFunctionCall1(int2_numeric, newval2));
  
! 	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
  }
  
  Datum
  int4_accum(PG_FUNCTION_ARGS)
  {
! 	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
! 	Datum		newval4 = PG_GETARG_DATUM(1);
! 	Numeric		newval;
  
! 	newval = DatumGetNumeric(DirectFunctionCall1(int4_numeric, newval4));
  
! 	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
  }
  
  Datum
  int8_accum(PG_FUNCTION_ARGS)
  {
! 	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
! 	Datum		newval8 = PG_GETARG_DATUM(1);
! 	Numeric		newval;
  
! 	newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
  
! 	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
  }
  
  /*
   * Optimized case for average of int8.
   */
  Datum
  int8_avg_accum(PG_FUNCTION_ARGS)
  {
! 	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
! 	Datum		newval8 = PG_GETARG_DATUM(1);
! 	Numeric		newval;
! 
! 	newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
  
! 	PG_RETURN_ARRAYTYPE_P(do_numeric_avg_accum(transarray, newval));
  }
  
  
  Datum
  numeric_avg(PG_FUNCTION_ARGS)
  {
! 	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
! 	Datum	   *transdatums;
! 	int			ndatums;
! 	Numeric		N,
! 				sumX;
! 
! 	/* We assume the input is array of numeric */
! 	deconstruct_array(transarray,
! 					  NUMERICOID, -1, false, 'i',
! 					  &transdatums, NULL, &ndatums);
! 	if (ndatums != 2)
! 		elog(ERROR, "expected 2-element numeric array");
! 	N = DatumGetNumeric(transdatums[0]);
! 	sumX = DatumGetNumeric(transdatums[1]);
  
! 	/* SQL defines AVG of no values to be NULL */
! 	/* N is zero iff no digits (cf. numeric_uminus) */
! 	if (NUMERIC_NDIGITS(N) == 0)
  		PG_RETURN_NULL();
  
! 	PG_RETURN_DATUM(DirectFunctionCall2(numeric_div,
! 										NumericGetDatum(sumX),
! 										NumericGetDatum(N)));
  }
  
  /*
   * Workhorse routine for the standard deviance and variance
!  * aggregates. 'transarray' is the aggregate's transition
!  * array. 'variance' specifies whether we should calculate the
   * variance or the standard deviation. 'sample' indicates whether the
   * caller is interested in the sample or the population
   * variance/stddev.
--- 2627,2776 ----
  Datum
  int2_accum(PG_FUNCTION_ARGS)
  {
! 	NumericAggState *state;
  
! 	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
  
! 	if (!PG_ARGISNULL(1))
! 	{
! 		Datum		newval2 = PG_GETARG_DATUM(1);
! 		Numeric		newval;
! 
! 		/* On the first time through, create the state variable. */
! 		if (state == NULL)
! 			state = makeNumericAggState(fcinfo, true);
! 		
! 		newval = DatumGetNumeric(DirectFunctionCall1(int2_numeric, newval2));
! 		do_numeric_accum(state, newval);
! 	}
! 
! 	if (state == NULL)
! 		PG_RETURN_NULL();
! 	else
! 		PG_RETURN_POINTER(state);
  }
  
+ 
  Datum
  int4_accum(PG_FUNCTION_ARGS)
  {
! 	NumericAggState *state;
! 
! 	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
  
! 	if (!PG_ARGISNULL(1))
! 	{
! 		Datum		newval4 = PG_GETARG_DATUM(1);
! 		Numeric		newval;
! 
! 		/* On the first time through, create the state variable. */
! 		if (state == NULL)
! 			state = makeNumericAggState(fcinfo, true);
! 		
! 		newval = DatumGetNumeric(DirectFunctionCall1(int4_numeric, newval4));
! 		do_numeric_accum(state, newval);
! 	}
  
! 	if (state == NULL)
! 		PG_RETURN_NULL();
! 	else
! 		PG_RETURN_POINTER(state);
  }
  
+ 
  Datum
  int8_accum(PG_FUNCTION_ARGS)
  {
! 	NumericAggState *state;
  
! 	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
! 
! 	if (!PG_ARGISNULL(1))
! 	{
! 		Datum		newval8 = PG_GETARG_DATUM(1);
! 		Numeric		newval;
! 
! 		/* On the first time through, create the state variable. */
! 		if (state == NULL)
! 			state = makeNumericAggState(fcinfo, true);
! 		
! 		newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
! 		do_numeric_accum(state, newval);
! 	}
  
! 	if (state == NULL)
! 		PG_RETURN_NULL();
! 	else
! 		PG_RETURN_POINTER(state);
  }
  
+ 
  /*
   * Optimized case for average of int8.
   */
  Datum
  int8_avg_accum(PG_FUNCTION_ARGS)
  {
! 	NumericAggState *state;	
! 	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
  
! 	if (!PG_ARGISNULL(1))
! 	{
! 		Datum		newval8 = PG_GETARG_DATUM(1);
! 		Numeric		newval;
! 
! 		/* On the first time through, create the state variable. */
! 		if (state == NULL)
! 			state = makeNumericAggState(fcinfo, false);
! 		
! 		newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
! 		do_numeric_accum(state, newval);
! 	}
!  
! 	if (state == NULL)
! 		PG_RETURN_NULL();
! 	else
! 		PG_RETURN_POINTER(state);
  }
  
  
  Datum
  numeric_avg(PG_FUNCTION_ARGS)
  {
! 	Datum 		 		N_datum;
! 	Datum 				sumX_datum;
! 	NumericAggState 	*state;
  
! 	if (PG_ARGISNULL(0))
  		PG_RETURN_NULL();
  
! 	state = (NumericAggState *) PG_GETARG_POINTER(0);
! 
! 	N_datum = DirectFunctionCall1(int8_numeric, Int64GetDatum(state->N));
! 	sumX_datum = NumericGetDatum(make_result(&state->sumX));
! 
! 	PG_RETURN_DATUM(DirectFunctionCall2(numeric_div, sumX_datum, N_datum));
  }
  
+ 
+ Datum
+ numeric_sum(PG_FUNCTION_ARGS)
+ {
+ 	NumericAggState 	*state;
+ 
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+  
+ 	state = (NumericAggState *) PG_GETARG_POINTER(0);
+ 
+ 	PG_RETURN_NUMERIC(make_result(&(state->sumX)));
+ }
+ 
+ 
  /*
   * Workhorse routine for the standard deviance and variance
!  * aggregates. 'state' is aggregate's transition state.
!  * 'variance' specifies whether we should calculate the
   * variance or the standard deviation. 'sample' indicates whether the
   * caller is interested in the sample or the population
   * variance/stddev.
***************
*** 2667,2682 **** numeric_avg(PG_FUNCTION_ARGS)
   * *is_null is set to true and NULL is returned.
   */
  static Numeric
! numeric_stddev_internal(ArrayType *transarray,
  						bool variance, bool sample,
  						bool *is_null)
  {
! 	Datum	   *transdatums;
! 	int			ndatums;
! 	Numeric		N,
! 				sumX,
! 				sumX2,
! 				res;
  	NumericVar	vN,
  				vsumX,
  				vsumX2,
--- 2779,2789 ----
   * *is_null is set to true and NULL is returned.
   */
  static Numeric
! numeric_stddev_internal(NumericAggState *state,
  						bool variance, bool sample,
  						bool *is_null)
  {
! 	Numeric		res;
  	NumericVar	vN,
  				vsumX,
  				vsumX2,
***************
*** 2684,2705 **** numeric_stddev_internal(ArrayType *transarray,
  	NumericVar *comp;
  	int			rscale;
  
  	*is_null = false;
  
! 	/* We assume the input is array of numeric */
! 	deconstruct_array(transarray,
! 					  NUMERICOID, -1, false, 'i',
! 					  &transdatums, NULL, &ndatums);
! 	if (ndatums != 3)
! 		elog(ERROR, "expected 3-element numeric array");
! 	N = DatumGetNumeric(transdatums[0]);
! 	sumX = DatumGetNumeric(transdatums[1]);
! 	sumX2 = DatumGetNumeric(transdatums[2]);
! 
! 	if (NUMERIC_IS_NAN(N) || NUMERIC_IS_NAN(sumX) || NUMERIC_IS_NAN(sumX2))
  		return make_result(&const_nan);
  
! 	init_var_from_num(N, &vN);
  
  	/*
  	 * Sample stddev and variance are undefined when N <= 1; population stddev
--- 2791,2814 ----
  	NumericVar *comp;
  	int			rscale;
  
+ 	if (state == NULL)
+ 	{
+ 		*is_null = true;
+ 		return NULL;
+ 	}
+ 
  	*is_null = false;
  
! 	if (state->isNaN)
  		return make_result(&const_nan);
  
! 	init_var(&vN);
! 	init_var(&vsumX);
! 	init_var(&vsumX2);
! 
! 	int8_to_numericvar(state->N, &vN);
! 	set_var_from_var(&(state->sumX), &vsumX);
! 	set_var_from_var(&(state->sumX2), &vsumX2);
  
  	/*
  	 * Sample stddev and variance are undefined when N <= 1; population stddev
***************
*** 2719,2726 **** numeric_stddev_internal(ArrayType *transarray,
  	init_var(&vNminus1);
  	sub_var(&vN, &const_one, &vNminus1);
  
! 	init_var_from_num(sumX, &vsumX);
! 	init_var_from_num(sumX2, &vsumX2);
  
  	/* compute rscale for mul_var calls */
  	rscale = vsumX.dscale * 2;
--- 2828,2835 ----
  	init_var(&vNminus1);
  	sub_var(&vN, &const_one, &vNminus1);
  
! 	set_var_from_var(&(state->sumX), &vsumX);
! 	set_var_from_var(&(state->sumX2), &vsumX2);
  
  	/* compute rscale for mul_var calls */
  	rscale = vsumX.dscale * 2;
***************
*** 2761,2767 **** numeric_var_samp(PG_FUNCTION_ARGS)
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
  								  true, true, &is_null);
  
  	if (is_null)
--- 2870,2876 ----
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
  								  true, true, &is_null);
  
  	if (is_null)
***************
*** 2776,2782 **** numeric_stddev_samp(PG_FUNCTION_ARGS)
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
  								  false, true, &is_null);
  
  	if (is_null)
--- 2885,2891 ----
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
  								  false, true, &is_null);
  
  	if (is_null)
***************
*** 2791,2797 **** numeric_var_pop(PG_FUNCTION_ARGS)
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
  								  true, false, &is_null);
  
  	if (is_null)
--- 2900,2906 ----
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
  								  true, false, &is_null);
  
  	if (is_null)
***************
*** 2806,2812 **** numeric_stddev_pop(PG_FUNCTION_ARGS)
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
  								  false, false, &is_null);
  
  	if (is_null)
--- 2915,2921 ----
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
  								  false, false, &is_null);
  
  	if (is_null)
*** a/src/bin/pg_dump/pg_dump.c
--- b/src/bin/pg_dump/pg_dump.c
***************
*** 11402,11413 **** dumpAgg(Archive *fout, AggInfo *agginfo)
--- 11402,11415 ----
  	int			i_aggfinalfn;
  	int			i_aggsortop;
  	int			i_aggtranstype;
+ 	int 		i_aggtransspace;
  	int			i_agginitval;
  	int			i_convertok;
  	const char *aggtransfn;
  	const char *aggfinalfn;
  	const char *aggsortop;
  	const char *aggtranstype;
+ 	const char *aggtransspace;
  	const char *agginitval;
  	bool		convertok;
  
***************
*** 11425,11436 **** dumpAgg(Archive *fout, AggInfo *agginfo)
  	selectSourceSchema(fout, agginfo->aggfn.dobj.namespace->dobj.name);
  
  	/* Get aggregate-specific details */
! 	if (fout->remoteVersion >= 80100)
  	{
  		appendPQExpBuffer(query, "SELECT aggtransfn, "
  						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
  						  "aggsortop::pg_catalog.regoperator, "
! 						  "agginitval, "
  						  "'t'::boolean AS convertok "
  					  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
  						  "WHERE a.aggfnoid = p.oid "
--- 11427,11450 ----
  	selectSourceSchema(fout, agginfo->aggfn.dobj.namespace->dobj.name);
  
  	/* Get aggregate-specific details */
! 	if (fout->remoteVersion >= 90300)
! 	{
! 		appendPQExpBuffer(query, "SELECT aggtransfn, "
! 						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
! 						  "aggsortop::pg_catalog.regoperator, "
! 						  "aggtransspace, agginitval, "
! 						  "'t'::boolean AS convertok "
! 					  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
! 						  "WHERE a.aggfnoid = p.oid "
! 						  "AND p.oid = '%u'::pg_catalog.oid",
! 						  agginfo->aggfn.dobj.catId.oid);
! 	}
! 	else if (fout->remoteVersion >= 80100)
  	{
  		appendPQExpBuffer(query, "SELECT aggtransfn, "
  						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
  						  "aggsortop::pg_catalog.regoperator, "
! 						  "0 AS aggtransspace, agginitval, "
  						  "'t'::boolean AS convertok "
  					  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
  						  "WHERE a.aggfnoid = p.oid "
***************
*** 11442,11448 **** dumpAgg(Archive *fout, AggInfo *agginfo)
  		appendPQExpBuffer(query, "SELECT aggtransfn, "
  						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
  						  "0 AS aggsortop, "
! 						  "agginitval, "
  						  "'t'::boolean AS convertok "
  					  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
  						  "WHERE a.aggfnoid = p.oid "
--- 11456,11462 ----
  		appendPQExpBuffer(query, "SELECT aggtransfn, "
  						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
  						  "0 AS aggsortop, "
! 						  "0 AS aggtransspace, agginitval, "
  						  "'t'::boolean AS convertok "
  					  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
  						  "WHERE a.aggfnoid = p.oid "
***************
*** 11454,11460 **** dumpAgg(Archive *fout, AggInfo *agginfo)
  		appendPQExpBuffer(query, "SELECT aggtransfn, aggfinalfn, "
  						  "format_type(aggtranstype, NULL) AS aggtranstype, "
  						  "0 AS aggsortop, "
! 						  "agginitval, "
  						  "'t'::boolean AS convertok "
  						  "FROM pg_aggregate "
  						  "WHERE oid = '%u'::oid",
--- 11468,11474 ----
  		appendPQExpBuffer(query, "SELECT aggtransfn, aggfinalfn, "
  						  "format_type(aggtranstype, NULL) AS aggtranstype, "
  						  "0 AS aggsortop, "
! 						  "0 AS aggtransspace, agginitval, "
  						  "'t'::boolean AS convertok "
  						  "FROM pg_aggregate "
  						  "WHERE oid = '%u'::oid",
***************
*** 11466,11472 **** dumpAgg(Archive *fout, AggInfo *agginfo)
  						  "aggfinalfn, "
  						  "(SELECT typname FROM pg_type WHERE oid = aggtranstype1) AS aggtranstype, "
  						  "0 AS aggsortop, "
! 						  "agginitval1 AS agginitval, "
  						  "(aggtransfn2 = 0 and aggtranstype2 = 0 and agginitval2 is null) AS convertok "
  						  "FROM pg_aggregate "
  						  "WHERE oid = '%u'::oid",
--- 11480,11486 ----
  						  "aggfinalfn, "
  						  "(SELECT typname FROM pg_type WHERE oid = aggtranstype1) AS aggtranstype, "
  						  "0 AS aggsortop, "
! 						  "0 AS aggtransspace, agginitval1 AS agginitval, "
  						  "(aggtransfn2 = 0 and aggtranstype2 = 0 and agginitval2 is null) AS convertok "
  						  "FROM pg_aggregate "
  						  "WHERE oid = '%u'::oid",
***************
*** 11479,11484 **** dumpAgg(Archive *fout, AggInfo *agginfo)
--- 11493,11499 ----
  	i_aggfinalfn = PQfnumber(res, "aggfinalfn");
  	i_aggsortop = PQfnumber(res, "aggsortop");
  	i_aggtranstype = PQfnumber(res, "aggtranstype");
+ 	i_aggtransspace = PQfnumber(res, "aggtransspace");
  	i_agginitval = PQfnumber(res, "agginitval");
  	i_convertok = PQfnumber(res, "convertok");
  
***************
*** 11486,11491 **** dumpAgg(Archive *fout, AggInfo *agginfo)
--- 11501,11507 ----
  	aggfinalfn = PQgetvalue(res, 0, i_aggfinalfn);
  	aggsortop = PQgetvalue(res, 0, i_aggsortop);
  	aggtranstype = PQgetvalue(res, 0, i_aggtranstype);
+ 	aggtransspace = PQgetvalue(res, 0, i_aggtransspace);
  	agginitval = PQgetvalue(res, 0, i_agginitval);
  	convertok = (PQgetvalue(res, 0, i_convertok)[0] == 't');
  
***************
*** 11522,11527 **** dumpAgg(Archive *fout, AggInfo *agginfo)
--- 11538,11549 ----
  						  fmtId(aggtranstype));
  	}
  
+ 	if (strcmp(aggtransspace, "0") != 0)
+ 	{
+ 		appendPQExpBuffer(details, ",\n    SSPACE = %s",
+ 						  aggtransspace);
+ 	}
+ 
  	if (!PQgetisnull(res, 0, i_agginitval))
  	{
  		appendPQExpBuffer(details, ",\n    INITCOND = ");
*** a/src/include/catalog/pg_aggregate.h
--- b/src/include/catalog/pg_aggregate.h
***************
*** 44,49 **** CATALOG(pg_aggregate,2600) BKI_WITHOUT_OIDS
--- 44,50 ----
  	regproc		aggfinalfn;
  	Oid			aggsortop;
  	Oid			aggtranstype;
+ 	int32		aggtransspace;
  
  #ifdef CATALOG_VARLEN			/* variable-length fields start here */
  	text		agginitval;
***************
*** 62,74 **** typedef FormData_pg_aggregate *Form_pg_aggregate;
   * ----------------
   */
  
! #define Natts_pg_aggregate				6
  #define Anum_pg_aggregate_aggfnoid		1
  #define Anum_pg_aggregate_aggtransfn	2
  #define Anum_pg_aggregate_aggfinalfn	3
  #define Anum_pg_aggregate_aggsortop		4
  #define Anum_pg_aggregate_aggtranstype	5
! #define Anum_pg_aggregate_agginitval	6
  
  
  /* ----------------
--- 63,76 ----
   * ----------------
   */
  
! #define Natts_pg_aggregate				7
  #define Anum_pg_aggregate_aggfnoid		1
  #define Anum_pg_aggregate_aggtransfn	2
  #define Anum_pg_aggregate_aggfinalfn	3
  #define Anum_pg_aggregate_aggsortop		4
  #define Anum_pg_aggregate_aggtranstype	5
! #define Anum_pg_aggregate_aggtransspace	6
! #define Anum_pg_aggregate_agginitval	7
  
  
  /* ----------------
***************
*** 77,239 **** typedef FormData_pg_aggregate *Form_pg_aggregate;
   */
  
  /* avg */
! DATA(insert ( 2100	int8_avg_accum	numeric_avg		0	1231	"{0,0}" ));
! DATA(insert ( 2101	int4_avg_accum	int8_avg		0	1016	"{0,0}" ));
! DATA(insert ( 2102	int2_avg_accum	int8_avg		0	1016	"{0,0}" ));
! DATA(insert ( 2103	numeric_avg_accum	numeric_avg		0	1231	"{0,0}" ));
! DATA(insert ( 2104	float4_accum	float8_avg		0	1022	"{0,0,0}" ));
! DATA(insert ( 2105	float8_accum	float8_avg		0	1022	"{0,0,0}" ));
! DATA(insert ( 2106	interval_accum	interval_avg	0	1187	"{0 second,0 second}" ));
  
  /* sum */
! DATA(insert ( 2107	int8_sum		-				0	1700	_null_ ));
! DATA(insert ( 2108	int4_sum		-				0	20		_null_ ));
! DATA(insert ( 2109	int2_sum		-				0	20		_null_ ));
! DATA(insert ( 2110	float4pl		-				0	700		_null_ ));
! DATA(insert ( 2111	float8pl		-				0	701		_null_ ));
! DATA(insert ( 2112	cash_pl			-				0	790		_null_ ));
! DATA(insert ( 2113	interval_pl		-				0	1186	_null_ ));
! DATA(insert ( 2114	numeric_add		-				0	1700	_null_ ));
  
  /* max */
! DATA(insert ( 2115	int8larger		-				413		20		_null_ ));
! DATA(insert ( 2116	int4larger		-				521		23		_null_ ));
! DATA(insert ( 2117	int2larger		-				520		21		_null_ ));
! DATA(insert ( 2118	oidlarger		-				610		26		_null_ ));
! DATA(insert ( 2119	float4larger	-				623		700		_null_ ));
! DATA(insert ( 2120	float8larger	-				674		701		_null_ ));
! DATA(insert ( 2121	int4larger		-				563		702		_null_ ));
! DATA(insert ( 2122	date_larger		-				1097	1082	_null_ ));
! DATA(insert ( 2123	time_larger		-				1112	1083	_null_ ));
! DATA(insert ( 2124	timetz_larger	-				1554	1266	_null_ ));
! DATA(insert ( 2125	cashlarger		-				903		790		_null_ ));
! DATA(insert ( 2126	timestamp_larger	-			2064	1114	_null_ ));
! DATA(insert ( 2127	timestamptz_larger	-			1324	1184	_null_ ));
! DATA(insert ( 2128	interval_larger -				1334	1186	_null_ ));
! DATA(insert ( 2129	text_larger		-				666		25		_null_ ));
! DATA(insert ( 2130	numeric_larger	-				1756	1700	_null_ ));
! DATA(insert ( 2050	array_larger	-				1073	2277	_null_ ));
! DATA(insert ( 2244	bpchar_larger	-				1060	1042	_null_ ));
! DATA(insert ( 2797	tidlarger		-				2800	27		_null_ ));
! DATA(insert ( 3526	enum_larger		-				3519	3500	_null_ ));
  
  /* min */
! DATA(insert ( 2131	int8smaller		-				412		20		_null_ ));
! DATA(insert ( 2132	int4smaller		-				97		23		_null_ ));
! DATA(insert ( 2133	int2smaller		-				95		21		_null_ ));
! DATA(insert ( 2134	oidsmaller		-				609		26		_null_ ));
! DATA(insert ( 2135	float4smaller	-				622		700		_null_ ));
! DATA(insert ( 2136	float8smaller	-				672		701		_null_ ));
! DATA(insert ( 2137	int4smaller		-				562		702		_null_ ));
! DATA(insert ( 2138	date_smaller	-				1095	1082	_null_ ));
! DATA(insert ( 2139	time_smaller	-				1110	1083	_null_ ));
! DATA(insert ( 2140	timetz_smaller	-				1552	1266	_null_ ));
! DATA(insert ( 2141	cashsmaller		-				902		790		_null_ ));
! DATA(insert ( 2142	timestamp_smaller	-			2062	1114	_null_ ));
! DATA(insert ( 2143	timestamptz_smaller -			1322	1184	_null_ ));
! DATA(insert ( 2144	interval_smaller	-			1332	1186	_null_ ));
! DATA(insert ( 2145	text_smaller	-				664		25		_null_ ));
! DATA(insert ( 2146	numeric_smaller -				1754	1700	_null_ ));
! DATA(insert ( 2051	array_smaller	-				1072	2277	_null_ ));
! DATA(insert ( 2245	bpchar_smaller	-				1058	1042	_null_ ));
! DATA(insert ( 2798	tidsmaller		-				2799	27		_null_ ));
! DATA(insert ( 3527	enum_smaller	-				3518	3500	_null_ ));
  
  /* count */
! DATA(insert ( 2147	int8inc_any		-				0		20		"0" ));
! DATA(insert ( 2803	int8inc			-				0		20		"0" ));
  
  /* var_pop */
! DATA(insert ( 2718	int8_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
! DATA(insert ( 2719	int4_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
! DATA(insert ( 2720	int2_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
! DATA(insert ( 2721	float4_accum	float8_var_pop 0	1022	"{0,0,0}" ));
! DATA(insert ( 2722	float8_accum	float8_var_pop 0	1022	"{0,0,0}" ));
! DATA(insert ( 2723	numeric_accum  numeric_var_pop 0	1231	"{0,0,0}" ));
  
  /* var_samp */
! DATA(insert ( 2641	int8_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
! DATA(insert ( 2642	int4_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
! DATA(insert ( 2643	int2_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
! DATA(insert ( 2644	float4_accum	float8_var_samp 0	1022	"{0,0,0}" ));
! DATA(insert ( 2645	float8_accum	float8_var_samp 0	1022	"{0,0,0}" ));
! DATA(insert ( 2646	numeric_accum  numeric_var_samp 0	1231	"{0,0,0}" ));
  
  /* variance: historical Postgres syntax for var_samp */
! DATA(insert ( 2148	int8_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
! DATA(insert ( 2149	int4_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
! DATA(insert ( 2150	int2_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
! DATA(insert ( 2151	float4_accum	float8_var_samp 0	1022	"{0,0,0}" ));
! DATA(insert ( 2152	float8_accum	float8_var_samp 0	1022	"{0,0,0}" ));
! DATA(insert ( 2153	numeric_accum  numeric_var_samp 0	1231	"{0,0,0}" ));
  
  /* stddev_pop */
! DATA(insert ( 2724	int8_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
! DATA(insert ( 2725	int4_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
! DATA(insert ( 2726	int2_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
! DATA(insert ( 2727	float4_accum	float8_stddev_pop	0	1022	"{0,0,0}" ));
! DATA(insert ( 2728	float8_accum	float8_stddev_pop	0	1022	"{0,0,0}" ));
! DATA(insert ( 2729	numeric_accum	numeric_stddev_pop	0	1231	"{0,0,0}" ));
  
  /* stddev_samp */
! DATA(insert ( 2712	int8_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
! DATA(insert ( 2713	int4_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
! DATA(insert ( 2714	int2_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
! DATA(insert ( 2715	float4_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
! DATA(insert ( 2716	float8_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
! DATA(insert ( 2717	numeric_accum	numeric_stddev_samp 0	1231	"{0,0,0}" ));
  
  /* stddev: historical Postgres syntax for stddev_samp */
! DATA(insert ( 2154	int8_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
! DATA(insert ( 2155	int4_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
! DATA(insert ( 2156	int2_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
! DATA(insert ( 2157	float4_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
! DATA(insert ( 2158	float8_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
! DATA(insert ( 2159	numeric_accum	numeric_stddev_samp 0	1231	"{0,0,0}" ));
  
  /* SQL2003 binary regression aggregates */
! DATA(insert ( 2818	int8inc_float8_float8		-				0	20		"0" ));
! DATA(insert ( 2819	float8_regr_accum	float8_regr_sxx			0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2820	float8_regr_accum	float8_regr_syy			0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2821	float8_regr_accum	float8_regr_sxy			0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2822	float8_regr_accum	float8_regr_avgx		0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2823	float8_regr_accum	float8_regr_avgy		0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2824	float8_regr_accum	float8_regr_r2			0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2825	float8_regr_accum	float8_regr_slope		0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2826	float8_regr_accum	float8_regr_intercept	0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2827	float8_regr_accum	float8_covar_pop		0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2828	float8_regr_accum	float8_covar_samp		0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2829	float8_regr_accum	float8_corr				0	1022	"{0,0,0,0,0,0}" ));
  
  /* boolean-and and boolean-or */
! DATA(insert ( 2517	booland_statefunc	-			58	16		_null_ ));
! DATA(insert ( 2518	boolor_statefunc	-			59	16		_null_ ));
! DATA(insert ( 2519	booland_statefunc	-			58	16		_null_ ));
  
  /* bitwise integer */
! DATA(insert ( 2236 int2and		  -					0	21		_null_ ));
! DATA(insert ( 2237 int2or		  -					0	21		_null_ ));
! DATA(insert ( 2238 int4and		  -					0	23		_null_ ));
! DATA(insert ( 2239 int4or		  -					0	23		_null_ ));
! DATA(insert ( 2240 int8and		  -					0	20		_null_ ));
! DATA(insert ( 2241 int8or		  -					0	20		_null_ ));
! DATA(insert ( 2242 bitand		  -					0	1560	_null_ ));
! DATA(insert ( 2243 bitor		  -					0	1560	_null_ ));
  
  /* xml */
! DATA(insert ( 2901 xmlconcat2	  -					0	142		_null_ ));
  
  /* array */
! DATA(insert ( 2335	array_agg_transfn	array_agg_finalfn		0	2281	_null_ ));
  
  /* text */
! DATA(insert ( 3538	string_agg_transfn	string_agg_finalfn		0	2281	_null_ ));
  
  /* bytea */
! DATA(insert ( 3545	bytea_string_agg_transfn	bytea_string_agg_finalfn		0	2281	_null_ ));
  
  /* json */
! DATA(insert ( 3175	json_agg_transfn	json_agg_finalfn		0	2281	_null_ ));
  
  /*
   * prototypes for functions in pg_aggregate.c
--- 79,241 ----
   */
  
  /* avg */
! DATA(insert ( 2100	int8_avg_accum		numeric_avg		0	2281	128	_null_ ));
! DATA(insert ( 2101	int4_avg_accum		int8_avg		0	1016	0	"{0,0}" ));
! DATA(insert ( 2102	int2_avg_accum		int8_avg		0	1016	0	"{0,0}" ));
! DATA(insert ( 2103	numeric_avg_accum		numeric_avg		0	2281	128	_null_ ));
! DATA(insert ( 2104	float4_accum		float8_avg		0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2105	float8_accum		float8_avg		0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2106	interval_accum		interval_avg	0	1187	0	"{0 second,0 second}" ));
  
  /* sum */
! DATA(insert ( 2107	int8_avg_accum	numeric_sum		0	2281	128	_null_ ));
! DATA(insert ( 2108	int4_sum		-				0	20		0	_null_ ));
! DATA(insert ( 2109	int2_sum		-				0	20		0	_null_ ));
! DATA(insert ( 2110	float4pl		-				0	700		0	_null_ ));
! DATA(insert ( 2111	float8pl		-				0	701		0	_null_ ));
! DATA(insert ( 2112	cash_pl			-				0	790		0	_null_ ));
! DATA(insert ( 2113	interval_pl		-				0	1186	0	_null_ ));
! DATA(insert ( 2114	numeric_avg_accum	numeric_sum	0	2281	128	_null_ ));
  
  /* max */
! DATA(insert ( 2115	int8larger		-				413		20		0	_null_ ));
! DATA(insert ( 2116	int4larger		-				521		23		0	_null_ ));
! DATA(insert ( 2117	int2larger		-				520		21		0	_null_ ));
! DATA(insert ( 2118	oidlarger		-				610		26		0	_null_ ));
! DATA(insert ( 2119	float4larger	-				623		700		0	_null_ ));
! DATA(insert ( 2120	float8larger	-				674		701		0	_null_ ));
! DATA(insert ( 2121	int4larger		-				563		702		0	_null_ ));
! DATA(insert ( 2122	date_larger		-				1097	1082	0	_null_ ));
! DATA(insert ( 2123	time_larger		-				1112	1083	0	_null_ ));
! DATA(insert ( 2124	timetz_larger	-				1554	1266	0	_null_ ));
! DATA(insert ( 2125	cashlarger		-				903		790		0	_null_ ));
! DATA(insert ( 2126	timestamp_larger	-			2064	1114	0	_null_ ));
! DATA(insert ( 2127	timestamptz_larger	-			1324	1184	0	_null_ ));
! DATA(insert ( 2128	interval_larger -				1334	1186	0	_null_ ));
! DATA(insert ( 2129	text_larger		-				666		25		0	_null_ ));
! DATA(insert ( 2130	numeric_larger	-				1756	1700	0	_null_ ));
! DATA(insert ( 2050	array_larger	-				1073	2277	0	_null_ ));
! DATA(insert ( 2244	bpchar_larger	-				1060	1042	0	_null_ ));
! DATA(insert ( 2797	tidlarger		-				2800	27		0	_null_ ));
! DATA(insert ( 3526	enum_larger		-				3519	3500	0	_null_ ));
  
  /* min */
! DATA(insert ( 2131	int8smaller		-				412		20		0	_null_ ));
! DATA(insert ( 2132	int4smaller		-				97		23		0	_null_ ));
! DATA(insert ( 2133	int2smaller		-				95		21		0	_null_ ));
! DATA(insert ( 2134	oidsmaller		-				609		26		0	_null_ ));
! DATA(insert ( 2135	float4smaller	-				622		700		0	_null_ ));
! DATA(insert ( 2136	float8smaller	-				672		701		0	_null_ ));
! DATA(insert ( 2137	int4smaller		-				562		702		0	_null_ ));
! DATA(insert ( 2138	date_smaller	-				1095	1082	0	_null_ ));
! DATA(insert ( 2139	time_smaller	-				1110	1083	0	_null_ ));
! DATA(insert ( 2140	timetz_smaller	-				1552	1266	0	_null_ ));
! DATA(insert ( 2141	cashsmaller		-				902		790		0	_null_ ));
! DATA(insert ( 2142	timestamp_smaller	-			2062	1114	0	_null_ ));
! DATA(insert ( 2143	timestamptz_smaller -			1322	1184	0	_null_ ));
! DATA(insert ( 2144	interval_smaller	-			1332	1186	0	_null_ ));
! DATA(insert ( 2145	text_smaller	-				664		25		0	_null_ ));
! DATA(insert ( 2146	numeric_smaller -				1754	1700	0	_null_ ));
! DATA(insert ( 2051	array_smaller	-				1072	2277	0	_null_ ));
! DATA(insert ( 2245	bpchar_smaller	-				1058	1042	0	_null_ ));
! DATA(insert ( 2798	tidsmaller		-				2799	27		0	_null_ ));
! DATA(insert ( 3527	enum_smaller	-				3518	3500	0	_null_ ));
  
  /* count */
! DATA(insert ( 2147	int8inc_any		-				0		20		0	"0" ));
! DATA(insert ( 2803	int8inc			-				0		20		0	"0" ));
  
  /* var_pop */
! DATA(insert ( 2718	int8_accum	numeric_var_pop 0	2281	128	_null_ ));
! DATA(insert ( 2719	int4_accum	numeric_var_pop 0	2281	128	_null_ ));
! DATA(insert ( 2720	int2_accum	numeric_var_pop 0	2281	128	_null_ ));
! DATA(insert ( 2721	float4_accum	float8_var_pop 0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2722	float8_accum	float8_var_pop 0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2723	numeric_accum  numeric_var_pop 0	2281	128	_null_ ));
  
  /* var_samp */
! DATA(insert ( 2641	int8_accum	numeric_var_samp	0	2281	128	_null_ ));
! DATA(insert ( 2642	int4_accum	numeric_var_samp	0	2281	128	_null_ ));
! DATA(insert ( 2643	int2_accum	numeric_var_samp	0	2281	128	_null_ ));
! DATA(insert ( 2644	float4_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2645	float8_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2646	numeric_accum  numeric_var_samp 0	2281	128	_null_ ));
  
  /* variance: historical Postgres syntax for var_samp */
! DATA(insert ( 2148	int8_accum	numeric_var_samp	0	2281	128	_null_ ));
! DATA(insert ( 2149	int4_accum	numeric_var_samp	0	2281	128	_null_ ));
! DATA(insert ( 2150	int2_accum	numeric_var_samp	0	2281	128	_null_ ));
! DATA(insert ( 2151	float4_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2152	float8_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2153	numeric_accum  numeric_var_samp 0	2281	128	_null_ ));
  
  /* stddev_pop */
! DATA(insert ( 2724	int8_accum	numeric_stddev_pop		0	2281	128	_null_ ));
! DATA(insert ( 2725	int4_accum	numeric_stddev_pop		0	2281	128	_null_ ));
! DATA(insert ( 2726	int2_accum	numeric_stddev_pop		0	2281	128	_null_ ));
! DATA(insert ( 2727	float4_accum	float8_stddev_pop	0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2728	float8_accum	float8_stddev_pop	0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2729	numeric_accum	numeric_stddev_pop	0	2281	128	_null_ ));
  
  /* stddev_samp */
! DATA(insert ( 2712	int8_accum	numeric_stddev_samp		0	2281	128	_null_ ));
! DATA(insert ( 2713	int4_accum	numeric_stddev_samp		0	2281	128	_null_ ));
! DATA(insert ( 2714	int2_accum	numeric_stddev_samp		0	2281	128	_null_ ));
! DATA(insert ( 2715	float4_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2716	float8_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2717	numeric_accum	numeric_stddev_samp 0	2281	128	_null_ ));
  
  /* stddev: historical Postgres syntax for stddev_samp */
! DATA(insert ( 2154	int8_accum	numeric_stddev_samp		0	2281	128	_null_ ));
! DATA(insert ( 2155	int4_accum	numeric_stddev_samp		0	2281	128	_null_ ));
! DATA(insert ( 2156	int2_accum	numeric_stddev_samp		0	2281	128	_null_ ));
! DATA(insert ( 2157	float4_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2158	float8_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2159	numeric_accum	numeric_stddev_samp 0	2281	128	_null_ ));
  
  /* SQL2003 binary regression aggregates */
! DATA(insert ( 2818	int8inc_float8_float8		-				0	20		0	"0" ));
! DATA(insert ( 2819	float8_regr_accum	float8_regr_sxx			0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2820	float8_regr_accum	float8_regr_syy			0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2821	float8_regr_accum	float8_regr_sxy			0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2822	float8_regr_accum	float8_regr_avgx		0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2823	float8_regr_accum	float8_regr_avgy		0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2824	float8_regr_accum	float8_regr_r2			0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2825	float8_regr_accum	float8_regr_slope		0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2826	float8_regr_accum	float8_regr_intercept	0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2827	float8_regr_accum	float8_covar_pop		0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2828	float8_regr_accum	float8_covar_samp		0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2829	float8_regr_accum	float8_corr				0	1022	0	"{0,0,0,0,0,0}" ));
  
  /* boolean-and and boolean-or */
! DATA(insert ( 2517	booland_statefunc	-			58	16		0	_null_ ));
! DATA(insert ( 2518	boolor_statefunc	-			59	16		0	_null_ ));
! DATA(insert ( 2519	booland_statefunc	-			58	16		0	_null_ ));
  
  /* bitwise integer */
! DATA(insert ( 2236 int2and		  -					0	21		0	_null_ ));
! DATA(insert ( 2237 int2or		  -					0	21		0	_null_ ));
! DATA(insert ( 2238 int4and		  -					0	23		0	_null_ ));
! DATA(insert ( 2239 int4or		  -					0	23		0	_null_ ));
! DATA(insert ( 2240 int8and		  -					0	20		0	_null_ ));
! DATA(insert ( 2241 int8or		  -					0	20		0	_null_ ));
! DATA(insert ( 2242 bitand		  -					0	1560	0	_null_ ));
! DATA(insert ( 2243 bitor		  -					0	1560	0	_null_ ));
  
  /* xml */
! DATA(insert ( 2901 xmlconcat2	  -					0	142		0	_null_ ));
  
  /* array */
! DATA(insert ( 2335	array_agg_transfn	array_agg_finalfn		0	2281	0	_null_ ));
  
  /* text */
! DATA(insert ( 3538	string_agg_transfn	string_agg_finalfn		0	2281	0	_null_ ));
  
  /* bytea */
! DATA(insert ( 3545	bytea_string_agg_transfn	bytea_string_agg_finalfn		0	2281	0	_null_ ));
  
  /* json */
! DATA(insert ( 3175	json_agg_transfn	json_agg_finalfn		0	2281	0	_null_ ));
  
  /*
   * prototypes for functions in pg_aggregate.c
***************
*** 246,251 **** extern Oid AggregateCreate(const char *aggName,
--- 248,254 ----
  				List *aggfinalfnName,
  				List *aggsortopName,
  				Oid aggTransType,
+ 				int32 aggTransSpace,
  				const char *agginitval);
  
  #endif   /* PG_AGGREGATE_H */
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
***************
*** 2381,2407 **** DATA(insert OID = 2513 (  float8_stddev_pop PGNSP PGUID 12 1 0 0 0 f f f f t f i
  DESCR("aggregate final function");
  DATA(insert OID = 1832 (  float8_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 701 "1022" _null_ _null_ _null_ _null_ float8_stddev_samp _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 1833 (  numeric_accum    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 1700" _null_ _null_ _null_ _null_ numeric_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 2858 (  numeric_avg_accum    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 1700" _null_ _null_ _null_ _null_ numeric_avg_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1834 (  int2_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 21" _null_ _null_ _null_ _null_ int2_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1835 (  int4_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 23" _null_ _null_ _null_ _null_ int4_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1836 (  int8_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 20" _null_ _null_ _null_ _null_ int8_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 2746 (  int8_avg_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 20" _null_ _null_ _null_ _null_ int8_avg_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1837 (  numeric_avg	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_avg _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 2514 (  numeric_var_pop  PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_var_pop _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 1838 (  numeric_var_samp PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_var_samp _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 2596 (  numeric_stddev_pop PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_	numeric_stddev_pop _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 1839 (  numeric_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_stddev_samp _null_ _null_ _null_ ));
  DESCR("aggregate final function");
  DATA(insert OID = 1840 (  int2_sum		   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 20 "20 21" _null_ _null_ _null_ _null_ int2_sum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
--- 2381,2409 ----
  DESCR("aggregate final function");
  DATA(insert OID = 1832 (  float8_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 701 "1022" _null_ _null_ _null_ _null_ float8_stddev_samp _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 1833 (  numeric_accum    PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 1700" _null_ _null_ _null_ _null_ numeric_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 2858 (  numeric_avg_accum    PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 1700" _null_ _null_ _null_ _null_ numeric_avg_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1834 (  int2_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 21" _null_ _null_ _null_ _null_ int2_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1835 (  int4_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 23" _null_ _null_ _null_ _null_ int4_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1836 (  int8_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 20" _null_ _null_ _null_ _null_ int8_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 2746 (  int8_avg_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 20" _null_ _null_ _null_ _null_ int8_avg_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1837 (  numeric_avg	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_avg _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 3179 (  numeric_sum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_sum _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 2514 (  numeric_var_pop  PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_var_pop _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 1838 (  numeric_var_samp PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_var_samp _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 2596 (  numeric_stddev_pop PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_	numeric_stddev_pop _null_ _null_ _null_ ));
! DESCR("aggregate final function");
! DATA(insert OID = 1839 (  numeric_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_stddev_samp _null_ _null_ _null_ ));
  DESCR("aggregate final function");
  DATA(insert OID = 1840 (  int2_sum		   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 20 "20 21" _null_ _null_ _null_ _null_ int2_sum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
*** a/src/include/commands/defrem.h
--- b/src/include/commands/defrem.h
***************
*** 122,127 **** extern Datum transformGenericOptions(Oid catalogId,
--- 122,128 ----
  extern char *defGetString(DefElem *def);
  extern double defGetNumeric(DefElem *def);
  extern bool defGetBoolean(DefElem *def);
+ extern int32 defGetInt32(DefElem *def);
  extern int64 defGetInt64(DefElem *def);
  extern List *defGetQualifiedName(DefElem *def);
  extern TypeName *defGetTypeName(DefElem *def);
*** a/src/include/utils/builtins.h
--- b/src/include/utils/builtins.h
***************
*** 981,986 **** extern Datum int4_accum(PG_FUNCTION_ARGS);
--- 981,987 ----
  extern Datum int8_accum(PG_FUNCTION_ARGS);
  extern Datum int8_avg_accum(PG_FUNCTION_ARGS);
  extern Datum numeric_avg(PG_FUNCTION_ARGS);
+ extern Datum numeric_sum(PG_FUNCTION_ARGS);
  extern Datum numeric_var_pop(PG_FUNCTION_ARGS);
  extern Datum numeric_var_samp(PG_FUNCTION_ARGS);
  extern Datum numeric_stddev_pop(PG_FUNCTION_ARGS);

*** a/doc/src/sgml/catalogs.sgml
--- b/doc/src/sgml/catalogs.sgml
***************
*** 373,378 ****
--- 373,384 ----
        <entry>Data type of the aggregate function's internal transition (state) data</entry>
       </row>
       <row>
+       <entry><structfield>aggtransspace</structfield></entry>
+       <entry><type>int4</type></entry>
+       <entry></entry>
+       <entry>Approximation for the average size of the aggregate function's internal transition (state) data</entry>
+      </row>
+      <row>
        <entry><structfield>agginitval</structfield></entry>
        <entry><type>text</type></entry>
        <entry></entry>
*** a/doc/src/sgml/ref/create_aggregate.sgml
--- b/doc/src/sgml/ref/create_aggregate.sgml
***************
*** 24,29 **** PostgreSQL documentation
--- 24,30 ----
  CREATE AGGREGATE <replaceable class="parameter">name</replaceable> ( [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">arg_name</replaceable> ] <replaceable class="parameter">arg_data_type</replaceable> [ , ... ] ) (
      SFUNC = <replaceable class="PARAMETER">sfunc</replaceable>,
      STYPE = <replaceable class="PARAMETER">state_data_type</replaceable>
+     [ , SSPACE = <replaceable class="PARAMETER">state_data_size</replaceable> ]
      [ , FINALFUNC = <replaceable class="PARAMETER">ffunc</replaceable> ]
      [ , INITCOND = <replaceable class="PARAMETER">initial_condition</replaceable> ]
      [ , SORTOP = <replaceable class="PARAMETER">sort_operator</replaceable> ]
***************
*** 35,40 **** CREATE AGGREGATE <replaceable class="PARAMETER">name</replaceable> (
--- 36,42 ----
      BASETYPE = <replaceable class="PARAMETER">base_type</replaceable>,
      SFUNC = <replaceable class="PARAMETER">sfunc</replaceable>,
      STYPE = <replaceable class="PARAMETER">state_data_type</replaceable>
+     [ , SSPACE = <replaceable class="PARAMETER">state_data_size</replaceable> ]
      [ , FINALFUNC = <replaceable class="PARAMETER">ffunc</replaceable> ]
      [ , INITCOND = <replaceable class="PARAMETER">initial_condition</replaceable> ]
      [ , SORTOP = <replaceable class="PARAMETER">sort_operator</replaceable> ]
***************
*** 265,270 **** SELECT col FROM tab ORDER BY col USING sortop LIMIT 1;
--- 267,284 ----
     </varlistentry>
  
     <varlistentry>
+     <term><replaceable class="PARAMETER">state_data_size</replaceable></term>
+     <listitem>
+      <para>
+       Approximate average size (in bytes) of aggregate's state value. 
+       Planner uses this value to approximate the memory required for 
+       the aggregation. If this value is not provided, a default value is 
+       used based on state_data_type.
+      </para>
+     </listitem>
+    </varlistentry>
+ 
+    <varlistentry>
      <term><replaceable class="PARAMETER">ffunc</replaceable></term>
      <listitem>
       <para>
*** a/src/backend/catalog/pg_aggregate.c
--- b/src/backend/catalog/pg_aggregate.c
***************
*** 55,60 **** AggregateCreate(const char *aggName,
--- 55,61 ----
  				List *aggfinalfnName,
  				List *aggsortopName,
  				Oid aggTransType,
+ 				int32 aggTransSpace,
  				const char *agginitval)
  {
  	Relation	aggdesc;
***************
*** 273,278 **** AggregateCreate(const char *aggName,
--- 274,280 ----
  	values[Anum_pg_aggregate_aggfinalfn - 1] = ObjectIdGetDatum(finalfn);
  	values[Anum_pg_aggregate_aggsortop - 1] = ObjectIdGetDatum(sortop);
  	values[Anum_pg_aggregate_aggtranstype - 1] = ObjectIdGetDatum(aggTransType);
+ 	values[Anum_pg_aggregate_aggtransspace - 1] = Int32GetDatum(aggTransSpace);
  	if (agginitval)
  		values[Anum_pg_aggregate_agginitval - 1] = CStringGetTextDatum(agginitval);
  	else
*** a/src/backend/commands/aggregatecmds.c
--- b/src/backend/commands/aggregatecmds.c
***************
*** 68,73 **** DefineAggregate(List *name, List *args, bool oldstyle, List *parameters,
--- 68,74 ----
  	ArrayType  *parameterNames;
  	List	   *parameterDefaults;
  	Oid			transTypeId;
+ 	int32		transSpace = 0;
  	char		transTypeType;
  	ListCell   *pl;
  
***************
*** 102,107 **** DefineAggregate(List *name, List *args, bool oldstyle, List *parameters,
--- 103,110 ----
  			transType = defGetTypeName(defel);
  		else if (pg_strcasecmp(defel->defname, "stype1") == 0)
  			transType = defGetTypeName(defel);
+ 		else if (pg_strcasecmp(defel->defname, "sspace") == 0)
+ 			transSpace = defGetInt32(defel);
  		else if (pg_strcasecmp(defel->defname, "initcond") == 0)
  			initval = defGetString(defel);
  		else if (pg_strcasecmp(defel->defname, "initcond1") == 0)
***************
*** 248,252 **** DefineAggregate(List *name, List *args, bool oldstyle, List *parameters,
--- 251,256 ----
  						   finalfuncName,		/* final function name */
  						   sortoperatorName,	/* sort operator name */
  						   transTypeId, /* transition data type */
+ 						   transSpace,			/* transition space */
  						   initval);	/* initial condition */
  }
*** a/src/backend/commands/define.c
--- b/src/backend/commands/define.c
***************
*** 165,170 **** defGetBoolean(DefElem *def)
--- 165,194 ----
  }
  
  /*
+  * Extract an int32 value from a DefElem.
+  */
+ int32
+ defGetInt32(DefElem *def)
+ {
+ 	if (def->arg == NULL)
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_SYNTAX_ERROR),
+ 				 errmsg("%s requires an integer value",
+ 						def->defname)));
+ 	switch (nodeTag(def->arg))
+ 	{
+ 		case T_Integer:
+ 			return (int32) intVal(def->arg);
+ 		default:
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_SYNTAX_ERROR),
+ 					 errmsg("%s requires an integer value",
+ 							def->defname)));
+ 	}
+ 	return 0;					/* keep compiler quiet */
+ }
+ 
+ /*
   * Extract an int64 value from a DefElem.
   */
  int64
*** a/src/backend/optimizer/util/clauses.c
--- b/src/backend/optimizer/util/clauses.c
***************
*** 461,466 **** count_agg_clauses_walker(Node *node, count_agg_clauses_context *context)
--- 461,467 ----
  		Oid			aggtransfn;
  		Oid			aggfinalfn;
  		Oid			aggtranstype;
+ 		int32 		aggtransspace;
  		QualCost	argcosts;
  		Oid		   *inputTypes;
  		int			numArguments;
***************
*** 478,483 **** count_agg_clauses_walker(Node *node, count_agg_clauses_context *context)
--- 479,485 ----
  		aggtransfn = aggform->aggtransfn;
  		aggfinalfn = aggform->aggfinalfn;
  		aggtranstype = aggform->aggtranstype;
+ 		aggtransspace = aggform->aggtransspace;
  		ReleaseSysCache(aggTuple);
  
  		/* count it */
***************
*** 533,545 **** count_agg_clauses_walker(Node *node, count_agg_clauses_context *context)
  			pfree(declaredArgTypes);
  		}
  
  		/*
  		 * If the transition type is pass-by-value then it doesn't add
  		 * anything to the required size of the hashtable.	If it is
  		 * pass-by-reference then we have to add the estimated size of the
  		 * value itself, plus palloc overhead.
  		 */
! 		if (!get_typbyval(aggtranstype))
  		{
  			int32		aggtranstypmod;
  			int32		avgwidth;
--- 535,555 ----
  			pfree(declaredArgTypes);
  		}
  
+ 		/* 
+ 		 * If approximate average space used by aggregate transition value is
+ 		 * specified in pg_aggregate, then use it for transitionSpace.
+ 		 */
+ 		if (aggtransspace > 0)
+ 		{
+ 			costs->transitionSpace += aggtransspace;
+ 		}
  		/*
  		 * If the transition type is pass-by-value then it doesn't add
  		 * anything to the required size of the hashtable.	If it is
  		 * pass-by-reference then we have to add the estimated size of the
  		 * value itself, plus palloc overhead.
  		 */
! 		else if (!get_typbyval(aggtranstype))
  		{
  			int32		aggtranstypmod;
  			int32		avgwidth;
*** a/src/backend/utils/adt/numeric.c
--- b/src/backend/utils/adt/numeric.c
***************
*** 2464,2571 **** numeric_float4(PG_FUNCTION_ARGS)
   *
   * Aggregate functions
   *
!  * The transition datatype for all these aggregates is a 3-element array
!  * of Numeric, holding the values N, sum(X), sum(X*X) in that order.
!  *
!  * We represent N as a numeric mainly to avoid having to build a special
!  * datatype; it's unlikely it'd overflow an int4, but ...
   *
   * ----------------------------------------------------------------------
   */
  
! static ArrayType *
! do_numeric_accum(ArrayType *transarray, Numeric newval)
  {
! 	Datum	   *transdatums;
! 	int			ndatums;
! 	Datum		N,
! 				sumX,
! 				sumX2;
! 	ArrayType  *result;
! 
! 	/* We assume the input is array of numeric */
! 	deconstruct_array(transarray,
! 					  NUMERICOID, -1, false, 'i',
! 					  &transdatums, NULL, &ndatums);
! 	if (ndatums != 3)
! 		elog(ERROR, "expected 3-element numeric array");
! 	N = transdatums[0];
! 	sumX = transdatums[1];
! 	sumX2 = transdatums[2];
! 
! 	N = DirectFunctionCall1(numeric_inc, N);
! 	sumX = DirectFunctionCall2(numeric_add, sumX,
! 							   NumericGetDatum(newval));
! 	sumX2 = DirectFunctionCall2(numeric_add, sumX2,
! 								DirectFunctionCall2(numeric_mul,
! 													NumericGetDatum(newval),
! 													NumericGetDatum(newval)));
! 
! 	transdatums[0] = N;
! 	transdatums[1] = sumX;
! 	transdatums[2] = sumX2;
! 
! 	result = construct_array(transdatums, 3,
! 							 NUMERICOID, -1, false, 'i');
  
! 	return result;
  }
  
! /*
!  * Improve avg performance by not caclulating sum(X*X).
!  */
! static ArrayType *
! do_numeric_avg_accum(ArrayType *transarray, Numeric newval)
  {
! 	Datum	   *transdatums;
! 	int			ndatums;
! 	Datum		N,
! 				sumX;
! 	ArrayType  *result;
! 
! 	/* We assume the input is array of numeric */
! 	deconstruct_array(transarray,
! 					  NUMERICOID, -1, false, 'i',
! 					  &transdatums, NULL, &ndatums);
! 	if (ndatums != 2)
! 		elog(ERROR, "expected 2-element numeric array");
! 	N = transdatums[0];
! 	sumX = transdatums[1];
! 
! 	N = DirectFunctionCall1(numeric_inc, N);
! 	sumX = DirectFunctionCall2(numeric_add, sumX,
! 							   NumericGetDatum(newval));
! 
! 	transdatums[0] = N;
! 	transdatums[1] = sumX;
! 
! 	result = construct_array(transdatums, 2,
! 							 NUMERICOID, -1, false, 'i');
  
! 	return result;
  }
  
  Datum
  numeric_accum(PG_FUNCTION_ARGS)
  {
! 	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
! 	Numeric		newval = PG_GETARG_NUMERIC(1);
  
! 	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
  }
  
  /*
   * Optimized case for average of numeric.
   */
  Datum
  numeric_avg_accum(PG_FUNCTION_ARGS)
  {
! 	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
! 	Numeric		newval = PG_GETARG_NUMERIC(1);
  
! 	PG_RETURN_ARRAYTYPE_P(do_numeric_avg_accum(transarray, newval));
  }
  
  /*
   * Integer data types all use Numeric accumulators to share code and
   * avoid risk of overflow.	For int2 and int4 inputs, Numeric accumulation
--- 2464,2620 ----
   *
   * Aggregate functions
   *
!  * The transition datatype for all these aggregates is a pointer to 
!  * a struct NumericAggState allocated in the aggregate context.
   *
   * ----------------------------------------------------------------------
   */
  
! typedef struct NumericAggState
! {
! 	bool 			first;
! 	bool 			isNaN;
! 	uint64			N;
! 	NumericVar 		sumX;
! 	NumericVar 		sumX2;
! 	bool 			calcSumX2;
! 	MemoryContext 	agg_context;
! } NumericAggState;
! 
! 
! static NumericAggState *
! makeNumericAggState(FunctionCallInfo fcinfo, bool calcSumX2)
  {
! 	NumericAggState 	*state;
! 	MemoryContext 		 agg_context;
! 	MemoryContext 		 old_context;
  
! 	if (!AggCheckCallContext(fcinfo, &agg_context))
! 	{
! 		elog(ERROR, "this is called in non-aggregate context");
! 	}
! 
! 	old_context = MemoryContextSwitchTo(agg_context);
! 
! 	state = palloc0(sizeof(NumericAggState));
! 	state->first = true;
! 	state->calcSumX2 = calcSumX2;
! 	state->agg_context = agg_context;
! 
! 	MemoryContextSwitchTo(old_context);
! 
! 	return state;
  }
  
! 
! static void
! do_numeric_accum(NumericAggState *state, Numeric newval)
  {
! 	NumericVar 		X;
! 	NumericVar 		X2;
! 	MemoryContext 	old_context;
! 	bool 			first;
! 	
! 	first = state->first;
! 	state->first = false;
! 	state->N++;
! 
! 	if (state->isNaN || NUMERIC_IS_NAN(newval))
! 	{
! 		state->isNaN = true;
! 		return;
! 	}
  
! 	init_var_from_num(newval, &X);
! 
! 	if (state->calcSumX2)
! 	{
! 		init_var(&X2);
! 		mul_var(&X, &X, &X2, X.dscale * 2);
! 	}
! 
! 	old_context = MemoryContextSwitchTo(state->agg_context);
! 
! 	if (!first)
! 	{
! 		NumericVar preSumX;
! 
! 		memcpy(&preSumX, &(state->sumX), sizeof(NumericVar));
! 		init_var(&(state->sumX));
! 		add_var(&X, &preSumX, &(state->sumX));
! 		free_var(&preSumX);
! 
! 		if (state->calcSumX2)
! 		{
! 			NumericVar preSumX2;
! 
! 			memcpy(&preSumX2, &(state->sumX2), sizeof(NumericVar));
! 			init_var(&(state->sumX2));
! 			add_var(&X2, &preSumX2, &(state->sumX2));
! 			free_var(&preSumX2);
! 		}
! 	}
! 	else
! 	{
! 		set_var_from_var(&X, &(state->sumX));
! 
! 		if (state->calcSumX2)
! 			set_var_from_var(&X2, &(state->sumX2));
! 	}
! 
! 	MemoryContextSwitchTo(old_context);
  }
  
+ 
  Datum
  numeric_accum(PG_FUNCTION_ARGS)
  {
! 	NumericAggState *state;
! 
! 	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
  
! 	if (!PG_ARGISNULL(1))
! 	{
! 		/* On the first time through, create the state variable. */
! 		if (state == NULL)
! 			state = makeNumericAggState(fcinfo, true);
! 		
! 		do_numeric_accum(state, PG_GETARG_NUMERIC(1));
! 	}
! 
! 	if (state == NULL)
! 		PG_RETURN_NULL();
! 	else
! 		PG_RETURN_POINTER(state);
  }
  
+ 
  /*
   * Optimized case for average of numeric.
   */
  Datum
  numeric_avg_accum(PG_FUNCTION_ARGS)
  {
! 	NumericAggState *state;
  
! 	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
! 
! 	if (!PG_ARGISNULL(1))
! 	{
! 		/* On the first time through, create the state variable. */
! 		if (state == NULL)
! 			state = makeNumericAggState(fcinfo, false);
! 		
! 		do_numeric_accum(state, PG_GETARG_NUMERIC(1));
! 	}
! 
! 	if (state == NULL)
! 		PG_RETURN_NULL();
! 	else
! 		PG_RETURN_POINTER(state);
  }
  
+ 
  /*
   * Integer data types all use Numeric accumulators to share code and
   * avoid risk of overflow.	For int2 and int4 inputs, Numeric accumulation
***************
*** 2578,2664 **** numeric_avg_accum(PG_FUNCTION_ARGS)
  Datum
  int2_accum(PG_FUNCTION_ARGS)
  {
! 	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
! 	Datum		newval2 = PG_GETARG_DATUM(1);
! 	Numeric		newval;
  
! 	newval = DatumGetNumeric(DirectFunctionCall1(int2_numeric, newval2));
  
! 	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
  }
  
  Datum
  int4_accum(PG_FUNCTION_ARGS)
  {
! 	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
! 	Datum		newval4 = PG_GETARG_DATUM(1);
! 	Numeric		newval;
  
! 	newval = DatumGetNumeric(DirectFunctionCall1(int4_numeric, newval4));
  
! 	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
  }
  
  Datum
  int8_accum(PG_FUNCTION_ARGS)
  {
! 	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
! 	Datum		newval8 = PG_GETARG_DATUM(1);
! 	Numeric		newval;
  
! 	newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
  
! 	PG_RETURN_ARRAYTYPE_P(do_numeric_accum(transarray, newval));
  }
  
  /*
   * Optimized case for average of int8.
   */
  Datum
  int8_avg_accum(PG_FUNCTION_ARGS)
  {
! 	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
! 	Datum		newval8 = PG_GETARG_DATUM(1);
! 	Numeric		newval;
! 
! 	newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
  
! 	PG_RETURN_ARRAYTYPE_P(do_numeric_avg_accum(transarray, newval));
  }
  
  
  Datum
  numeric_avg(PG_FUNCTION_ARGS)
  {
! 	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
! 	Datum	   *transdatums;
! 	int			ndatums;
! 	Numeric		N,
! 				sumX;
! 
! 	/* We assume the input is array of numeric */
! 	deconstruct_array(transarray,
! 					  NUMERICOID, -1, false, 'i',
! 					  &transdatums, NULL, &ndatums);
! 	if (ndatums != 2)
! 		elog(ERROR, "expected 2-element numeric array");
! 	N = DatumGetNumeric(transdatums[0]);
! 	sumX = DatumGetNumeric(transdatums[1]);
  
! 	/* SQL defines AVG of no values to be NULL */
! 	/* N is zero iff no digits (cf. numeric_uminus) */
! 	if (NUMERIC_NDIGITS(N) == 0)
  		PG_RETURN_NULL();
  
! 	PG_RETURN_DATUM(DirectFunctionCall2(numeric_div,
! 										NumericGetDatum(sumX),
! 										NumericGetDatum(N)));
  }
  
  /*
   * Workhorse routine for the standard deviance and variance
!  * aggregates. 'transarray' is the aggregate's transition
!  * array. 'variance' specifies whether we should calculate the
   * variance or the standard deviation. 'sample' indicates whether the
   * caller is interested in the sample or the population
   * variance/stddev.
--- 2627,2776 ----
  Datum
  int2_accum(PG_FUNCTION_ARGS)
  {
! 	NumericAggState *state;
  
! 	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
  
! 	if (!PG_ARGISNULL(1))
! 	{
! 		Datum		newval2 = PG_GETARG_DATUM(1);
! 		Numeric		newval;
! 
! 		/* On the first time through, create the state variable. */
! 		if (state == NULL)
! 			state = makeNumericAggState(fcinfo, true);
! 		
! 		newval = DatumGetNumeric(DirectFunctionCall1(int2_numeric, newval2));
! 		do_numeric_accum(state, newval);
! 	}
! 
! 	if (state == NULL)
! 		PG_RETURN_NULL();
! 	else
! 		PG_RETURN_POINTER(state);
  }
  
+ 
  Datum
  int4_accum(PG_FUNCTION_ARGS)
  {
! 	NumericAggState *state;
! 
! 	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
  
! 	if (!PG_ARGISNULL(1))
! 	{
! 		Datum		newval4 = PG_GETARG_DATUM(1);
! 		Numeric		newval;
! 
! 		/* On the first time through, create the state variable. */
! 		if (state == NULL)
! 			state = makeNumericAggState(fcinfo, true);
! 		
! 		newval = DatumGetNumeric(DirectFunctionCall1(int4_numeric, newval4));
! 		do_numeric_accum(state, newval);
! 	}
  
! 	if (state == NULL)
! 		PG_RETURN_NULL();
! 	else
! 		PG_RETURN_POINTER(state);
  }
  
+ 
  Datum
  int8_accum(PG_FUNCTION_ARGS)
  {
! 	NumericAggState *state;
  
! 	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
! 
! 	if (!PG_ARGISNULL(1))
! 	{
! 		Datum		newval8 = PG_GETARG_DATUM(1);
! 		Numeric		newval;
! 
! 		/* On the first time through, create the state variable. */
! 		if (state == NULL)
! 			state = makeNumericAggState(fcinfo, true);
! 		
! 		newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
! 		do_numeric_accum(state, newval);
! 	}
  
! 	if (state == NULL)
! 		PG_RETURN_NULL();
! 	else
! 		PG_RETURN_POINTER(state);
  }
  
+ 
  /*
   * Optimized case for average of int8.
   */
  Datum
  int8_avg_accum(PG_FUNCTION_ARGS)
  {
! 	NumericAggState *state;	
! 	state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
  
! 	if (!PG_ARGISNULL(1))
! 	{
! 		Datum		newval8 = PG_GETARG_DATUM(1);
! 		Numeric		newval;
! 
! 		/* On the first time through, create the state variable. */
! 		if (state == NULL)
! 			state = makeNumericAggState(fcinfo, false);
! 		
! 		newval = DatumGetNumeric(DirectFunctionCall1(int8_numeric, newval8));
! 		do_numeric_accum(state, newval);
! 	}
!  
! 	if (state == NULL)
! 		PG_RETURN_NULL();
! 	else
! 		PG_RETURN_POINTER(state);
  }
  
  
  Datum
  numeric_avg(PG_FUNCTION_ARGS)
  {
! 	Datum 		 		N_datum;
! 	Datum 				sumX_datum;
! 	NumericAggState 	*state;
  
! 	if (PG_ARGISNULL(0))
  		PG_RETURN_NULL();
  
! 	state = (NumericAggState *) PG_GETARG_POINTER(0);
! 
! 	N_datum = DirectFunctionCall1(int8_numeric, Int64GetDatum(state->N));
! 	sumX_datum = NumericGetDatum(make_result(&state->sumX));
! 
! 	PG_RETURN_DATUM(DirectFunctionCall2(numeric_div, sumX_datum, N_datum));
  }
  
+ 
+ Datum
+ numeric_sum(PG_FUNCTION_ARGS)
+ {
+ 	NumericAggState 	*state;
+ 
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+  
+ 	state = (NumericAggState *) PG_GETARG_POINTER(0);
+ 
+ 	PG_RETURN_NUMERIC(make_result(&(state->sumX)));
+ }
+ 
+ 
  /*
   * Workhorse routine for the standard deviance and variance
!  * aggregates. 'state' is aggregate's transition state.
!  * 'variance' specifies whether we should calculate the
   * variance or the standard deviation. 'sample' indicates whether the
   * caller is interested in the sample or the population
   * variance/stddev.
***************
*** 2667,2682 **** numeric_avg(PG_FUNCTION_ARGS)
   * *is_null is set to true and NULL is returned.
   */
  static Numeric
! numeric_stddev_internal(ArrayType *transarray,
  						bool variance, bool sample,
  						bool *is_null)
  {
! 	Datum	   *transdatums;
! 	int			ndatums;
! 	Numeric		N,
! 				sumX,
! 				sumX2,
! 				res;
  	NumericVar	vN,
  				vsumX,
  				vsumX2,
--- 2779,2789 ----
   * *is_null is set to true and NULL is returned.
   */
  static Numeric
! numeric_stddev_internal(NumericAggState *state,
  						bool variance, bool sample,
  						bool *is_null)
  {
! 	Numeric		res;
  	NumericVar	vN,
  				vsumX,
  				vsumX2,
***************
*** 2684,2705 **** numeric_stddev_internal(ArrayType *transarray,
  	NumericVar *comp;
  	int			rscale;
  
  	*is_null = false;
  
! 	/* We assume the input is array of numeric */
! 	deconstruct_array(transarray,
! 					  NUMERICOID, -1, false, 'i',
! 					  &transdatums, NULL, &ndatums);
! 	if (ndatums != 3)
! 		elog(ERROR, "expected 3-element numeric array");
! 	N = DatumGetNumeric(transdatums[0]);
! 	sumX = DatumGetNumeric(transdatums[1]);
! 	sumX2 = DatumGetNumeric(transdatums[2]);
! 
! 	if (NUMERIC_IS_NAN(N) || NUMERIC_IS_NAN(sumX) || NUMERIC_IS_NAN(sumX2))
  		return make_result(&const_nan);
  
! 	init_var_from_num(N, &vN);
  
  	/*
  	 * Sample stddev and variance are undefined when N <= 1; population stddev
--- 2791,2814 ----
  	NumericVar *comp;
  	int			rscale;
  
+ 	if (state == NULL)
+ 	{
+ 		*is_null = true;
+ 		return NULL;
+ 	}
+ 
  	*is_null = false;
  
! 	if (state->isNaN)
  		return make_result(&const_nan);
  
! 	init_var(&vN);
! 	init_var(&vsumX);
! 	init_var(&vsumX2);
! 
! 	int8_to_numericvar(state->N, &vN);
! 	set_var_from_var(&(state->sumX), &vsumX);
! 	set_var_from_var(&(state->sumX2), &vsumX2);
  
  	/*
  	 * Sample stddev and variance are undefined when N <= 1; population stddev
***************
*** 2719,2726 **** numeric_stddev_internal(ArrayType *transarray,
  	init_var(&vNminus1);
  	sub_var(&vN, &const_one, &vNminus1);
  
! 	init_var_from_num(sumX, &vsumX);
! 	init_var_from_num(sumX2, &vsumX2);
  
  	/* compute rscale for mul_var calls */
  	rscale = vsumX.dscale * 2;
--- 2828,2835 ----
  	init_var(&vNminus1);
  	sub_var(&vN, &const_one, &vNminus1);
  
! 	set_var_from_var(&(state->sumX), &vsumX);
! 	set_var_from_var(&(state->sumX2), &vsumX2);
  
  	/* compute rscale for mul_var calls */
  	rscale = vsumX.dscale * 2;
***************
*** 2761,2767 **** numeric_var_samp(PG_FUNCTION_ARGS)
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
  								  true, true, &is_null);
  
  	if (is_null)
--- 2870,2876 ----
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
  								  true, true, &is_null);
  
  	if (is_null)
***************
*** 2776,2782 **** numeric_stddev_samp(PG_FUNCTION_ARGS)
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
  								  false, true, &is_null);
  
  	if (is_null)
--- 2885,2891 ----
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
  								  false, true, &is_null);
  
  	if (is_null)
***************
*** 2791,2797 **** numeric_var_pop(PG_FUNCTION_ARGS)
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
  								  true, false, &is_null);
  
  	if (is_null)
--- 2900,2906 ----
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
  								  true, false, &is_null);
  
  	if (is_null)
***************
*** 2806,2812 **** numeric_stddev_pop(PG_FUNCTION_ARGS)
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal(PG_GETARG_ARRAYTYPE_P(0),
  								  false, false, &is_null);
  
  	if (is_null)
--- 2915,2921 ----
  	Numeric		res;
  	bool		is_null;
  
! 	res = numeric_stddev_internal((NumericAggState *) PG_GETARG_POINTER(0),
  								  false, false, &is_null);
  
  	if (is_null)
*** a/src/bin/pg_dump/pg_dump.c
--- b/src/bin/pg_dump/pg_dump.c
***************
*** 11419,11430 **** dumpAgg(Archive *fout, AggInfo *agginfo)
--- 11419,11432 ----
  	int			i_aggfinalfn;
  	int			i_aggsortop;
  	int			i_aggtranstype;
+ 	int			i_aggtransspace;
  	int			i_agginitval;
  	int			i_convertok;
  	const char *aggtransfn;
  	const char *aggfinalfn;
  	const char *aggsortop;
  	const char *aggtranstype;
+ 	const char *aggtransspace;
  	const char *agginitval;
  	bool		convertok;
  
***************
*** 11442,11453 **** dumpAgg(Archive *fout, AggInfo *agginfo)
  	selectSourceSchema(fout, agginfo->aggfn.dobj.namespace->dobj.name);
  
  	/* Get aggregate-specific details */
! 	if (fout->remoteVersion >= 80400)
  	{
  		appendPQExpBuffer(query, "SELECT aggtransfn, "
  						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
  						  "aggsortop::pg_catalog.regoperator, "
! 						  "agginitval, "
  						  "'t'::boolean AS convertok, "
  						  "pg_catalog.pg_get_function_arguments(p.oid) AS funcargs, "
  						  "pg_catalog.pg_get_function_identity_arguments(p.oid) AS funciargs "
--- 11444,11469 ----
  	selectSourceSchema(fout, agginfo->aggfn.dobj.namespace->dobj.name);
  
  	/* Get aggregate-specific details */
! 	if (fout->remoteVersion >= 90300)
! 	{
! 		appendPQExpBuffer(query, "SELECT aggtransfn, "
! 						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
! 						  "aggsortop::pg_catalog.regoperator, "
! 						  "aggtransspace, agginitval, "
! 						  "'t'::boolean AS convertok, "
! 						  "pg_catalog.pg_get_function_arguments(p.oid) AS funcargs, "
! 						  "pg_catalog.pg_get_function_identity_arguments(p.oid) AS funciargs "
! 					  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
! 						  "WHERE a.aggfnoid = p.oid "
! 						  "AND p.oid = '%u'::pg_catalog.oid",
! 						  agginfo->aggfn.dobj.catId.oid);
! 	}
! 	else if (fout->remoteVersion >= 80400)
  	{
  		appendPQExpBuffer(query, "SELECT aggtransfn, "
  						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
  						  "aggsortop::pg_catalog.regoperator, "
! 						  "0 AS aggtransspace, agginitval, "
  						  "'t'::boolean AS convertok, "
  						  "pg_catalog.pg_get_function_arguments(p.oid) AS funcargs, "
  						  "pg_catalog.pg_get_function_identity_arguments(p.oid) AS funciargs "
***************
*** 11461,11467 **** dumpAgg(Archive *fout, AggInfo *agginfo)
  		appendPQExpBuffer(query, "SELECT aggtransfn, "
  						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
  						  "aggsortop::pg_catalog.regoperator, "
! 						  "agginitval, "
  						  "'t'::boolean AS convertok "
  						  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
  						  "WHERE a.aggfnoid = p.oid "
--- 11477,11483 ----
  		appendPQExpBuffer(query, "SELECT aggtransfn, "
  						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
  						  "aggsortop::pg_catalog.regoperator, "
! 						  "0 AS aggtransspace, agginitval, "
  						  "'t'::boolean AS convertok "
  						  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
  						  "WHERE a.aggfnoid = p.oid "
***************
*** 11473,11479 **** dumpAgg(Archive *fout, AggInfo *agginfo)
  		appendPQExpBuffer(query, "SELECT aggtransfn, "
  						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
  						  "0 AS aggsortop, "
! 						  "agginitval, "
  						  "'t'::boolean AS convertok "
  					  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
  						  "WHERE a.aggfnoid = p.oid "
--- 11489,11495 ----
  		appendPQExpBuffer(query, "SELECT aggtransfn, "
  						  "aggfinalfn, aggtranstype::pg_catalog.regtype, "
  						  "0 AS aggsortop, "
! 						  "0 AS aggtransspace, agginitval, "
  						  "'t'::boolean AS convertok "
  					  "FROM pg_catalog.pg_aggregate a, pg_catalog.pg_proc p "
  						  "WHERE a.aggfnoid = p.oid "
***************
*** 11485,11491 **** dumpAgg(Archive *fout, AggInfo *agginfo)
  		appendPQExpBuffer(query, "SELECT aggtransfn, aggfinalfn, "
  						  "format_type(aggtranstype, NULL) AS aggtranstype, "
  						  "0 AS aggsortop, "
! 						  "agginitval, "
  						  "'t'::boolean AS convertok "
  						  "FROM pg_aggregate "
  						  "WHERE oid = '%u'::oid",
--- 11501,11507 ----
  		appendPQExpBuffer(query, "SELECT aggtransfn, aggfinalfn, "
  						  "format_type(aggtranstype, NULL) AS aggtranstype, "
  						  "0 AS aggsortop, "
! 						  "0 AS aggtransspace, agginitval, "
  						  "'t'::boolean AS convertok "
  						  "FROM pg_aggregate "
  						  "WHERE oid = '%u'::oid",
***************
*** 11497,11503 **** dumpAgg(Archive *fout, AggInfo *agginfo)
  						  "aggfinalfn, "
  						  "(SELECT typname FROM pg_type WHERE oid = aggtranstype1) AS aggtranstype, "
  						  "0 AS aggsortop, "
! 						  "agginitval1 AS agginitval, "
  						  "(aggtransfn2 = 0 and aggtranstype2 = 0 and agginitval2 is null) AS convertok "
  						  "FROM pg_aggregate "
  						  "WHERE oid = '%u'::oid",
--- 11513,11519 ----
  						  "aggfinalfn, "
  						  "(SELECT typname FROM pg_type WHERE oid = aggtranstype1) AS aggtranstype, "
  						  "0 AS aggsortop, "
! 						  "0 AS aggtransspace, agginitval1 AS agginitval, "
  						  "(aggtransfn2 = 0 and aggtranstype2 = 0 and agginitval2 is null) AS convertok "
  						  "FROM pg_aggregate "
  						  "WHERE oid = '%u'::oid",
***************
*** 11510,11515 **** dumpAgg(Archive *fout, AggInfo *agginfo)
--- 11526,11532 ----
  	i_aggfinalfn = PQfnumber(res, "aggfinalfn");
  	i_aggsortop = PQfnumber(res, "aggsortop");
  	i_aggtranstype = PQfnumber(res, "aggtranstype");
+ 	i_aggtransspace = PQfnumber(res, "aggtransspace");
  	i_agginitval = PQfnumber(res, "agginitval");
  	i_convertok = PQfnumber(res, "convertok");
  
***************
*** 11517,11522 **** dumpAgg(Archive *fout, AggInfo *agginfo)
--- 11534,11540 ----
  	aggfinalfn = PQgetvalue(res, 0, i_aggfinalfn);
  	aggsortop = PQgetvalue(res, 0, i_aggsortop);
  	aggtranstype = PQgetvalue(res, 0, i_aggtranstype);
+ 	aggtransspace = PQgetvalue(res, 0, i_aggtransspace);
  	agginitval = PQgetvalue(res, 0, i_agginitval);
  	convertok = (PQgetvalue(res, 0, i_convertok)[0] == 't');
  
***************
*** 11570,11575 **** dumpAgg(Archive *fout, AggInfo *agginfo)
--- 11588,11599 ----
  						  fmtId(aggtranstype));
  	}
  
+ 	if (strcmp(aggfinalfn, "0") != 0)
+ 	{
+ 		appendPQExpBuffer(details, ",\n    SSPACE = %s",
+ 						  aggtransspace);
+ 	}
+ 
  	if (!PQgetisnull(res, 0, i_agginitval))
  	{
  		appendPQExpBuffer(details, ",\n    INITCOND = ");
*** a/src/include/catalog/pg_aggregate.h
--- b/src/include/catalog/pg_aggregate.h
***************
*** 44,49 **** CATALOG(pg_aggregate,2600) BKI_WITHOUT_OIDS
--- 44,50 ----
  	regproc		aggfinalfn;
  	Oid			aggsortop;
  	Oid			aggtranstype;
+ 	int32		aggtransspace;
  
  #ifdef CATALOG_VARLEN			/* variable-length fields start here */
  	text		agginitval;
***************
*** 62,74 **** typedef FormData_pg_aggregate *Form_pg_aggregate;
   * ----------------
   */
  
! #define Natts_pg_aggregate				6
  #define Anum_pg_aggregate_aggfnoid		1
  #define Anum_pg_aggregate_aggtransfn	2
  #define Anum_pg_aggregate_aggfinalfn	3
  #define Anum_pg_aggregate_aggsortop		4
  #define Anum_pg_aggregate_aggtranstype	5
! #define Anum_pg_aggregate_agginitval	6
  
  
  /* ----------------
--- 63,76 ----
   * ----------------
   */
  
! #define Natts_pg_aggregate				7
  #define Anum_pg_aggregate_aggfnoid		1
  #define Anum_pg_aggregate_aggtransfn	2
  #define Anum_pg_aggregate_aggfinalfn	3
  #define Anum_pg_aggregate_aggsortop		4
  #define Anum_pg_aggregate_aggtranstype	5
! #define Anum_pg_aggregate_aggtransspace	6
! #define Anum_pg_aggregate_agginitval	7
  
  
  /* ----------------
***************
*** 77,239 **** typedef FormData_pg_aggregate *Form_pg_aggregate;
   */
  
  /* avg */
! DATA(insert ( 2100	int8_avg_accum	numeric_avg		0	1231	"{0,0}" ));
! DATA(insert ( 2101	int4_avg_accum	int8_avg		0	1016	"{0,0}" ));
! DATA(insert ( 2102	int2_avg_accum	int8_avg		0	1016	"{0,0}" ));
! DATA(insert ( 2103	numeric_avg_accum	numeric_avg		0	1231	"{0,0}" ));
! DATA(insert ( 2104	float4_accum	float8_avg		0	1022	"{0,0,0}" ));
! DATA(insert ( 2105	float8_accum	float8_avg		0	1022	"{0,0,0}" ));
! DATA(insert ( 2106	interval_accum	interval_avg	0	1187	"{0 second,0 second}" ));
  
  /* sum */
! DATA(insert ( 2107	int8_sum		-				0	1700	_null_ ));
! DATA(insert ( 2108	int4_sum		-				0	20		_null_ ));
! DATA(insert ( 2109	int2_sum		-				0	20		_null_ ));
! DATA(insert ( 2110	float4pl		-				0	700		_null_ ));
! DATA(insert ( 2111	float8pl		-				0	701		_null_ ));
! DATA(insert ( 2112	cash_pl			-				0	790		_null_ ));
! DATA(insert ( 2113	interval_pl		-				0	1186	_null_ ));
! DATA(insert ( 2114	numeric_add		-				0	1700	_null_ ));
  
  /* max */
! DATA(insert ( 2115	int8larger		-				413		20		_null_ ));
! DATA(insert ( 2116	int4larger		-				521		23		_null_ ));
! DATA(insert ( 2117	int2larger		-				520		21		_null_ ));
! DATA(insert ( 2118	oidlarger		-				610		26		_null_ ));
! DATA(insert ( 2119	float4larger	-				623		700		_null_ ));
! DATA(insert ( 2120	float8larger	-				674		701		_null_ ));
! DATA(insert ( 2121	int4larger		-				563		702		_null_ ));
! DATA(insert ( 2122	date_larger		-				1097	1082	_null_ ));
! DATA(insert ( 2123	time_larger		-				1112	1083	_null_ ));
! DATA(insert ( 2124	timetz_larger	-				1554	1266	_null_ ));
! DATA(insert ( 2125	cashlarger		-				903		790		_null_ ));
! DATA(insert ( 2126	timestamp_larger	-			2064	1114	_null_ ));
! DATA(insert ( 2127	timestamptz_larger	-			1324	1184	_null_ ));
! DATA(insert ( 2128	interval_larger -				1334	1186	_null_ ));
! DATA(insert ( 2129	text_larger		-				666		25		_null_ ));
! DATA(insert ( 2130	numeric_larger	-				1756	1700	_null_ ));
! DATA(insert ( 2050	array_larger	-				1073	2277	_null_ ));
! DATA(insert ( 2244	bpchar_larger	-				1060	1042	_null_ ));
! DATA(insert ( 2797	tidlarger		-				2800	27		_null_ ));
! DATA(insert ( 3526	enum_larger		-				3519	3500	_null_ ));
  
  /* min */
! DATA(insert ( 2131	int8smaller		-				412		20		_null_ ));
! DATA(insert ( 2132	int4smaller		-				97		23		_null_ ));
! DATA(insert ( 2133	int2smaller		-				95		21		_null_ ));
! DATA(insert ( 2134	oidsmaller		-				609		26		_null_ ));
! DATA(insert ( 2135	float4smaller	-				622		700		_null_ ));
! DATA(insert ( 2136	float8smaller	-				672		701		_null_ ));
! DATA(insert ( 2137	int4smaller		-				562		702		_null_ ));
! DATA(insert ( 2138	date_smaller	-				1095	1082	_null_ ));
! DATA(insert ( 2139	time_smaller	-				1110	1083	_null_ ));
! DATA(insert ( 2140	timetz_smaller	-				1552	1266	_null_ ));
! DATA(insert ( 2141	cashsmaller		-				902		790		_null_ ));
! DATA(insert ( 2142	timestamp_smaller	-			2062	1114	_null_ ));
! DATA(insert ( 2143	timestamptz_smaller -			1322	1184	_null_ ));
! DATA(insert ( 2144	interval_smaller	-			1332	1186	_null_ ));
! DATA(insert ( 2145	text_smaller	-				664		25		_null_ ));
! DATA(insert ( 2146	numeric_smaller -				1754	1700	_null_ ));
! DATA(insert ( 2051	array_smaller	-				1072	2277	_null_ ));
! DATA(insert ( 2245	bpchar_smaller	-				1058	1042	_null_ ));
! DATA(insert ( 2798	tidsmaller		-				2799	27		_null_ ));
! DATA(insert ( 3527	enum_smaller	-				3518	3500	_null_ ));
  
  /* count */
! DATA(insert ( 2147	int8inc_any		-				0		20		"0" ));
! DATA(insert ( 2803	int8inc			-				0		20		"0" ));
  
  /* var_pop */
! DATA(insert ( 2718	int8_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
! DATA(insert ( 2719	int4_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
! DATA(insert ( 2720	int2_accum	numeric_var_pop 0	1231	"{0,0,0}" ));
! DATA(insert ( 2721	float4_accum	float8_var_pop 0	1022	"{0,0,0}" ));
! DATA(insert ( 2722	float8_accum	float8_var_pop 0	1022	"{0,0,0}" ));
! DATA(insert ( 2723	numeric_accum  numeric_var_pop 0	1231	"{0,0,0}" ));
  
  /* var_samp */
! DATA(insert ( 2641	int8_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
! DATA(insert ( 2642	int4_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
! DATA(insert ( 2643	int2_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
! DATA(insert ( 2644	float4_accum	float8_var_samp 0	1022	"{0,0,0}" ));
! DATA(insert ( 2645	float8_accum	float8_var_samp 0	1022	"{0,0,0}" ));
! DATA(insert ( 2646	numeric_accum  numeric_var_samp 0	1231	"{0,0,0}" ));
  
  /* variance: historical Postgres syntax for var_samp */
! DATA(insert ( 2148	int8_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
! DATA(insert ( 2149	int4_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
! DATA(insert ( 2150	int2_accum	numeric_var_samp	0	1231	"{0,0,0}" ));
! DATA(insert ( 2151	float4_accum	float8_var_samp 0	1022	"{0,0,0}" ));
! DATA(insert ( 2152	float8_accum	float8_var_samp 0	1022	"{0,0,0}" ));
! DATA(insert ( 2153	numeric_accum  numeric_var_samp 0	1231	"{0,0,0}" ));
  
  /* stddev_pop */
! DATA(insert ( 2724	int8_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
! DATA(insert ( 2725	int4_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
! DATA(insert ( 2726	int2_accum	numeric_stddev_pop		0	1231	"{0,0,0}" ));
! DATA(insert ( 2727	float4_accum	float8_stddev_pop	0	1022	"{0,0,0}" ));
! DATA(insert ( 2728	float8_accum	float8_stddev_pop	0	1022	"{0,0,0}" ));
! DATA(insert ( 2729	numeric_accum	numeric_stddev_pop	0	1231	"{0,0,0}" ));
  
  /* stddev_samp */
! DATA(insert ( 2712	int8_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
! DATA(insert ( 2713	int4_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
! DATA(insert ( 2714	int2_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
! DATA(insert ( 2715	float4_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
! DATA(insert ( 2716	float8_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
! DATA(insert ( 2717	numeric_accum	numeric_stddev_samp 0	1231	"{0,0,0}" ));
  
  /* stddev: historical Postgres syntax for stddev_samp */
! DATA(insert ( 2154	int8_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
! DATA(insert ( 2155	int4_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
! DATA(insert ( 2156	int2_accum	numeric_stddev_samp		0	1231	"{0,0,0}" ));
! DATA(insert ( 2157	float4_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
! DATA(insert ( 2158	float8_accum	float8_stddev_samp	0	1022	"{0,0,0}" ));
! DATA(insert ( 2159	numeric_accum	numeric_stddev_samp 0	1231	"{0,0,0}" ));
  
  /* SQL2003 binary regression aggregates */
! DATA(insert ( 2818	int8inc_float8_float8		-				0	20		"0" ));
! DATA(insert ( 2819	float8_regr_accum	float8_regr_sxx			0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2820	float8_regr_accum	float8_regr_syy			0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2821	float8_regr_accum	float8_regr_sxy			0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2822	float8_regr_accum	float8_regr_avgx		0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2823	float8_regr_accum	float8_regr_avgy		0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2824	float8_regr_accum	float8_regr_r2			0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2825	float8_regr_accum	float8_regr_slope		0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2826	float8_regr_accum	float8_regr_intercept	0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2827	float8_regr_accum	float8_covar_pop		0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2828	float8_regr_accum	float8_covar_samp		0	1022	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2829	float8_regr_accum	float8_corr				0	1022	"{0,0,0,0,0,0}" ));
  
  /* boolean-and and boolean-or */
! DATA(insert ( 2517	booland_statefunc	-			58	16		_null_ ));
! DATA(insert ( 2518	boolor_statefunc	-			59	16		_null_ ));
! DATA(insert ( 2519	booland_statefunc	-			58	16		_null_ ));
  
  /* bitwise integer */
! DATA(insert ( 2236 int2and		  -					0	21		_null_ ));
! DATA(insert ( 2237 int2or		  -					0	21		_null_ ));
! DATA(insert ( 2238 int4and		  -					0	23		_null_ ));
! DATA(insert ( 2239 int4or		  -					0	23		_null_ ));
! DATA(insert ( 2240 int8and		  -					0	20		_null_ ));
! DATA(insert ( 2241 int8or		  -					0	20		_null_ ));
! DATA(insert ( 2242 bitand		  -					0	1560	_null_ ));
! DATA(insert ( 2243 bitor		  -					0	1560	_null_ ));
  
  /* xml */
! DATA(insert ( 2901 xmlconcat2	  -					0	142		_null_ ));
  
  /* array */
! DATA(insert ( 2335	array_agg_transfn	array_agg_finalfn		0	2281	_null_ ));
  
  /* text */
! DATA(insert ( 3538	string_agg_transfn	string_agg_finalfn		0	2281	_null_ ));
  
  /* bytea */
! DATA(insert ( 3545	bytea_string_agg_transfn	bytea_string_agg_finalfn		0	2281	_null_ ));
  
  /* json */
! DATA(insert ( 3175	json_agg_transfn	json_agg_finalfn		0	2281	_null_ ));
  
  /*
   * prototypes for functions in pg_aggregate.c
--- 79,241 ----
   */
  
  /* avg */
! DATA(insert ( 2100	int8_avg_accum		numeric_avg		0	2281	128	_null_ ));
! DATA(insert ( 2101	int4_avg_accum		int8_avg		0	1016	0	"{0,0}" ));
! DATA(insert ( 2102	int2_avg_accum		int8_avg		0	1016	0	"{0,0}" ));
! DATA(insert ( 2103	numeric_avg_accum		numeric_avg		0	2281	128	_null_ ));
! DATA(insert ( 2104	float4_accum		float8_avg		0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2105	float8_accum		float8_avg		0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2106	interval_accum		interval_avg	0	1187	0	"{0 second,0 second}" ));
  
  /* sum */
! DATA(insert ( 2107	int8_avg_accum	numeric_sum		0	2281	128	_null_ ));
! DATA(insert ( 2108	int4_sum		-				0	20		0	_null_ ));
! DATA(insert ( 2109	int2_sum		-				0	20		0	_null_ ));
! DATA(insert ( 2110	float4pl		-				0	700		0	_null_ ));
! DATA(insert ( 2111	float8pl		-				0	701		0	_null_ ));
! DATA(insert ( 2112	cash_pl			-				0	790		0	_null_ ));
! DATA(insert ( 2113	interval_pl		-				0	1186	0	_null_ ));
! DATA(insert ( 2114	numeric_avg_accum	numeric_sum	0	2281	128	_null_ ));
  
  /* max */
! DATA(insert ( 2115	int8larger		-				413		20		0	_null_ ));
! DATA(insert ( 2116	int4larger		-				521		23		0	_null_ ));
! DATA(insert ( 2117	int2larger		-				520		21		0	_null_ ));
! DATA(insert ( 2118	oidlarger		-				610		26		0	_null_ ));
! DATA(insert ( 2119	float4larger	-				623		700		0	_null_ ));
! DATA(insert ( 2120	float8larger	-				674		701		0	_null_ ));
! DATA(insert ( 2121	int4larger		-				563		702		0	_null_ ));
! DATA(insert ( 2122	date_larger		-				1097	1082	0	_null_ ));
! DATA(insert ( 2123	time_larger		-				1112	1083	0	_null_ ));
! DATA(insert ( 2124	timetz_larger	-				1554	1266	0	_null_ ));
! DATA(insert ( 2125	cashlarger		-				903		790		0	_null_ ));
! DATA(insert ( 2126	timestamp_larger	-			2064	1114	0	_null_ ));
! DATA(insert ( 2127	timestamptz_larger	-			1324	1184	0	_null_ ));
! DATA(insert ( 2128	interval_larger -				1334	1186	0	_null_ ));
! DATA(insert ( 2129	text_larger		-				666		25		0	_null_ ));
! DATA(insert ( 2130	numeric_larger	-				1756	1700	0	_null_ ));
! DATA(insert ( 2050	array_larger	-				1073	2277	0	_null_ ));
! DATA(insert ( 2244	bpchar_larger	-				1060	1042	0	_null_ ));
! DATA(insert ( 2797	tidlarger		-				2800	27		0	_null_ ));
! DATA(insert ( 3526	enum_larger		-				3519	3500	0	_null_ ));
  
  /* min */
! DATA(insert ( 2131	int8smaller		-				412		20		0	_null_ ));
! DATA(insert ( 2132	int4smaller		-				97		23		0	_null_ ));
! DATA(insert ( 2133	int2smaller		-				95		21		0	_null_ ));
! DATA(insert ( 2134	oidsmaller		-				609		26		0	_null_ ));
! DATA(insert ( 2135	float4smaller	-				622		700		0	_null_ ));
! DATA(insert ( 2136	float8smaller	-				672		701		0	_null_ ));
! DATA(insert ( 2137	int4smaller		-				562		702		0	_null_ ));
! DATA(insert ( 2138	date_smaller	-				1095	1082	0	_null_ ));
! DATA(insert ( 2139	time_smaller	-				1110	1083	0	_null_ ));
! DATA(insert ( 2140	timetz_smaller	-				1552	1266	0	_null_ ));
! DATA(insert ( 2141	cashsmaller		-				902		790		0	_null_ ));
! DATA(insert ( 2142	timestamp_smaller	-			2062	1114	0	_null_ ));
! DATA(insert ( 2143	timestamptz_smaller -			1322	1184	0	_null_ ));
! DATA(insert ( 2144	interval_smaller	-			1332	1186	0	_null_ ));
! DATA(insert ( 2145	text_smaller	-				664		25		0	_null_ ));
! DATA(insert ( 2146	numeric_smaller -				1754	1700	0	_null_ ));
! DATA(insert ( 2051	array_smaller	-				1072	2277	0	_null_ ));
! DATA(insert ( 2245	bpchar_smaller	-				1058	1042	0	_null_ ));
! DATA(insert ( 2798	tidsmaller		-				2799	27		0	_null_ ));
! DATA(insert ( 3527	enum_smaller	-				3518	3500	0	_null_ ));
  
  /* count */
! DATA(insert ( 2147	int8inc_any		-				0		20		0	"0" ));
! DATA(insert ( 2803	int8inc			-				0		20		0	"0" ));
  
  /* var_pop */
! DATA(insert ( 2718	int8_accum	numeric_var_pop 0	2281	128	_null_ ));
! DATA(insert ( 2719	int4_accum	numeric_var_pop 0	2281	128	_null_ ));
! DATA(insert ( 2720	int2_accum	numeric_var_pop 0	2281	128	_null_ ));
! DATA(insert ( 2721	float4_accum	float8_var_pop 0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2722	float8_accum	float8_var_pop 0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2723	numeric_accum  numeric_var_pop 0	2281	128	_null_ ));
  
  /* var_samp */
! DATA(insert ( 2641	int8_accum	numeric_var_samp	0	2281	128	_null_ ));
! DATA(insert ( 2642	int4_accum	numeric_var_samp	0	2281	128	_null_ ));
! DATA(insert ( 2643	int2_accum	numeric_var_samp	0	2281	128	_null_ ));
! DATA(insert ( 2644	float4_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2645	float8_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2646	numeric_accum  numeric_var_samp 0	2281	128	_null_ ));
  
  /* variance: historical Postgres syntax for var_samp */
! DATA(insert ( 2148	int8_accum	numeric_var_samp	0	2281	128	_null_ ));
! DATA(insert ( 2149	int4_accum	numeric_var_samp	0	2281	128	_null_ ));
! DATA(insert ( 2150	int2_accum	numeric_var_samp	0	2281	128	_null_ ));
! DATA(insert ( 2151	float4_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2152	float8_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2153	numeric_accum  numeric_var_samp 0	2281	128	_null_ ));
  
  /* stddev_pop */
! DATA(insert ( 2724	int8_accum	numeric_stddev_pop		0	2281	128	_null_ ));
! DATA(insert ( 2725	int4_accum	numeric_stddev_pop		0	2281	128	_null_ ));
! DATA(insert ( 2726	int2_accum	numeric_stddev_pop		0	2281	128	_null_ ));
! DATA(insert ( 2727	float4_accum	float8_stddev_pop	0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2728	float8_accum	float8_stddev_pop	0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2729	numeric_accum	numeric_stddev_pop	0	2281	128	_null_ ));
  
  /* stddev_samp */
! DATA(insert ( 2712	int8_accum	numeric_stddev_samp		0	2281	128	_null_ ));
! DATA(insert ( 2713	int4_accum	numeric_stddev_samp		0	2281	128	_null_ ));
! DATA(insert ( 2714	int2_accum	numeric_stddev_samp		0	2281	128	_null_ ));
! DATA(insert ( 2715	float4_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2716	float8_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2717	numeric_accum	numeric_stddev_samp 0	2281	128	_null_ ));
  
  /* stddev: historical Postgres syntax for stddev_samp */
! DATA(insert ( 2154	int8_accum	numeric_stddev_samp		0	2281	128	_null_ ));
! DATA(insert ( 2155	int4_accum	numeric_stddev_samp		0	2281	128	_null_ ));
! DATA(insert ( 2156	int2_accum	numeric_stddev_samp		0	2281	128	_null_ ));
! DATA(insert ( 2157	float4_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2158	float8_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
! DATA(insert ( 2159	numeric_accum	numeric_stddev_samp 0	2281	128	_null_ ));
  
  /* SQL2003 binary regression aggregates */
! DATA(insert ( 2818	int8inc_float8_float8		-				0	20		0	"0" ));
! DATA(insert ( 2819	float8_regr_accum	float8_regr_sxx			0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2820	float8_regr_accum	float8_regr_syy			0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2821	float8_regr_accum	float8_regr_sxy			0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2822	float8_regr_accum	float8_regr_avgx		0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2823	float8_regr_accum	float8_regr_avgy		0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2824	float8_regr_accum	float8_regr_r2			0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2825	float8_regr_accum	float8_regr_slope		0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2826	float8_regr_accum	float8_regr_intercept	0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2827	float8_regr_accum	float8_covar_pop		0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2828	float8_regr_accum	float8_covar_samp		0	1022	0	"{0,0,0,0,0,0}" ));
! DATA(insert ( 2829	float8_regr_accum	float8_corr				0	1022	0	"{0,0,0,0,0,0}" ));
  
  /* boolean-and and boolean-or */
! DATA(insert ( 2517	booland_statefunc	-			58	16		0	_null_ ));
! DATA(insert ( 2518	boolor_statefunc	-			59	16		0	_null_ ));
! DATA(insert ( 2519	booland_statefunc	-			58	16		0	_null_ ));
  
  /* bitwise integer */
! DATA(insert ( 2236 int2and		  -					0	21		0	_null_ ));
! DATA(insert ( 2237 int2or		  -					0	21		0	_null_ ));
! DATA(insert ( 2238 int4and		  -					0	23		0	_null_ ));
! DATA(insert ( 2239 int4or		  -					0	23		0	_null_ ));
! DATA(insert ( 2240 int8and		  -					0	20		0	_null_ ));
! DATA(insert ( 2241 int8or		  -					0	20		0	_null_ ));
! DATA(insert ( 2242 bitand		  -					0	1560	0	_null_ ));
! DATA(insert ( 2243 bitor		  -					0	1560	0	_null_ ));
  
  /* xml */
! DATA(insert ( 2901 xmlconcat2	  -					0	142		0	_null_ ));
  
  /* array */
! DATA(insert ( 2335	array_agg_transfn	array_agg_finalfn		0	2281	0	_null_ ));
  
  /* text */
! DATA(insert ( 3538	string_agg_transfn	string_agg_finalfn		0	2281	0	_null_ ));
  
  /* bytea */
! DATA(insert ( 3545	bytea_string_agg_transfn	bytea_string_agg_finalfn		0	2281	0	_null_ ));
  
  /* json */
! DATA(insert ( 3175	json_agg_transfn	json_agg_finalfn		0	2281	0	_null_ ));
  
  /*
   * prototypes for functions in pg_aggregate.c
***************
*** 250,255 **** extern Oid AggregateCreate(const char *aggName,
--- 252,258 ----
  				List *aggfinalfnName,
  				List *aggsortopName,
  				Oid aggTransType,
+ 				int32 aggTransSpace,
  				const char *agginitval);
  
  #endif   /* PG_AGGREGATE_H */
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
***************
*** 2381,2407 **** DATA(insert OID = 2513 (  float8_stddev_pop PGNSP PGUID 12 1 0 0 0 f f f f t f i
  DESCR("aggregate final function");
  DATA(insert OID = 1832 (  float8_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 701 "1022" _null_ _null_ _null_ _null_ float8_stddev_samp _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 1833 (  numeric_accum    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 1700" _null_ _null_ _null_ _null_ numeric_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 2858 (  numeric_avg_accum    PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 1700" _null_ _null_ _null_ _null_ numeric_avg_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1834 (  int2_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 21" _null_ _null_ _null_ _null_ int2_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1835 (  int4_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 23" _null_ _null_ _null_ _null_ int4_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1836 (  int8_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 20" _null_ _null_ _null_ _null_ int8_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 2746 (  int8_avg_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1231 "1231 20" _null_ _null_ _null_ _null_ int8_avg_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1837 (  numeric_avg	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_avg _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 2514 (  numeric_var_pop  PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_var_pop _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 1838 (  numeric_var_samp PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_var_samp _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 2596 (  numeric_stddev_pop PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_	numeric_stddev_pop _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 1839 (  numeric_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1231" _null_ _null_ _null_ _null_ numeric_stddev_samp _null_ _null_ _null_ ));
  DESCR("aggregate final function");
  DATA(insert OID = 1840 (  int2_sum		   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 20 "20 21" _null_ _null_ _null_ _null_ int2_sum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
--- 2381,2409 ----
  DESCR("aggregate final function");
  DATA(insert OID = 1832 (  float8_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 701 "1022" _null_ _null_ _null_ _null_ float8_stddev_samp _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 1833 (  numeric_accum    PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 1700" _null_ _null_ _null_ _null_ numeric_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 2858 (  numeric_avg_accum    PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 1700" _null_ _null_ _null_ _null_ numeric_avg_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1834 (  int2_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 21" _null_ _null_ _null_ _null_ int2_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1835 (  int4_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 23" _null_ _null_ _null_ _null_ int4_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1836 (  int8_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 20" _null_ _null_ _null_ _null_ int8_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 2746 (  int8_avg_accum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 20" _null_ _null_ _null_ _null_ int8_avg_accum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
! DATA(insert OID = 1837 (  numeric_avg	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_avg _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 3179 (  numeric_sum	   PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_sum _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 2514 (  numeric_var_pop  PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_var_pop _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 1838 (  numeric_var_samp PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_var_samp _null_ _null_ _null_ ));
  DESCR("aggregate final function");
! DATA(insert OID = 2596 (  numeric_stddev_pop PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_	numeric_stddev_pop _null_ _null_ _null_ ));
! DESCR("aggregate final function");
! DATA(insert OID = 1839 (  numeric_stddev_samp	PGNSP PGUID 12 1 0 0 0 f f f f f f i 1 0 1700 "2281" _null_ _null_ _null_ _null_ numeric_stddev_samp _null_ _null_ _null_ ));
  DESCR("aggregate final function");
  DATA(insert OID = 1840 (  int2_sum		   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 20 "20 21" _null_ _null_ _null_ _null_ int2_sum _null_ _null_ _null_ ));
  DESCR("aggregate transition function");
*** a/src/include/commands/defrem.h
--- b/src/include/commands/defrem.h
***************
*** 133,138 **** extern Datum transformGenericOptions(Oid catalogId,
--- 133,139 ----
  extern char *defGetString(DefElem *def);
  extern double defGetNumeric(DefElem *def);
  extern bool defGetBoolean(DefElem *def);
+ extern int32 defGetInt32(DefElem *def);
  extern int64 defGetInt64(DefElem *def);
  extern List *defGetQualifiedName(DefElem *def);
  extern TypeName *defGetTypeName(DefElem *def);
*** a/src/include/utils/builtins.h
--- b/src/include/utils/builtins.h
***************
*** 982,987 **** extern Datum int4_accum(PG_FUNCTION_ARGS);
--- 982,988 ----
  extern Datum int8_accum(PG_FUNCTION_ARGS);
  extern Datum int8_avg_accum(PG_FUNCTION_ARGS);
  extern Datum numeric_avg(PG_FUNCTION_ARGS);
+ extern Datum numeric_sum(PG_FUNCTION_ARGS);
  extern Datum numeric_var_pop(PG_FUNCTION_ARGS);
  extern Datum numeric_var_samp(PG_FUNCTION_ARGS);
  extern Datum numeric_stddev_pop(PG_FUNCTION_ARGS);
*** a/src/test/regress/expected/aggregates.out
--- b/src/test/regress/expected/aggregates.out
***************
*** 1262,1264 **** select least_agg(variadic array[q1,q2]) from int8_tbl;
--- 1262,1313 ----
   -4567890123456789
  (1 row)
  
+ -- verify correct calculations for null set
+ select sum(null::int4) from generate_series(1,1);
+  sum 
+ -----
+     
+ (1 row)
+ 
+ select sum(null::int8) from generate_series(1,1);
+  sum 
+ -----
+     
+ (1 row)
+ 
+ select sum(null::numeric) from generate_series(1,1);
+  sum 
+ -----
+     
+ (1 row)
+ 
+ select sum(null::float8) from generate_series(1,1);
+  sum 
+ -----
+     
+ (1 row)
+ 
+ select avg(null::int4) from generate_series(1,1);
+  avg 
+ -----
+     
+ (1 row)
+ 
+ select avg(null::int8) from generate_series(1,1);
+  avg 
+ -----
+     
+ (1 row)
+ 
+ select avg(null::numeric) from generate_series(1,1);
+  avg 
+ -----
+     
+ (1 row)
+ 
+ select avg(null::float8) from generate_series(1,1);
+  avg 
+ -----
+     
+ (1 row)
+ 
*** a/src/test/regress/sql/aggregates.sql
--- b/src/test/regress/sql/aggregates.sql
***************
*** 484,486 **** select aggfns(distinct a,b,c order by a,c using ~<~,b) filter (where a > 1)
--- 484,497 ----
  -- variadic aggregates
  select least_agg(q1,q2) from int8_tbl;
  select least_agg(variadic array[q1,q2]) from int8_tbl;
+ 
+ -- verify correct calculations for null set
+ select sum(null::int4) from generate_series(1,1);
+ select sum(null::int8) from generate_series(1,1);
+ select sum(null::numeric) from generate_series(1,1);
+ select sum(null::float8) from generate_series(1,1);
+ 
+ select avg(null::int4) from generate_series(1,1);
+ select avg(null::int8) from generate_series(1,1);
+ select avg(null::numeric) from generate_series(1,1);
+ select avg(null::float8) from generate_series(1,1);