diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index b25235c..bd07c70 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -12642,7 +12642,7 @@ NULL baz</literallayout>(3 rows)</entry>
        <type>double precision</type> for a floating-point argument,
        otherwise the same as the argument data type
       </entry>
-      <entry>All types apart from floating-point types</entry>
+      <entry>Yes</entry>
       <entry>the average (arithmetic mean) of all input values</entry>
      </row>
 
@@ -12900,7 +12900,7 @@ NULL baz</literallayout>(3 rows)</entry>
        <type>bigint</type> arguments, otherwise the same as the
        argument data type
       </entry>
-      <entry>All types apart from floating-point types</entry>
+      <entry>Yes</entry>
       <entry>sum of <replaceable class="parameter">expression</replaceable> across all input values</entry>
      </row>
 
@@ -13052,7 +13052,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       <entry>
        <type>double precision</type>
       </entry>
-      <entry>No</entry>
+      <entry>Yes</entry>
       <entry>correlation coefficient</entry>
      </row>
 
@@ -13073,7 +13073,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       <entry>
        <type>double precision</type>
       </entry>
-      <entry>No</entry>
+      <entry>Yes</entry>
       <entry>population covariance</entry>
      </row>
 
@@ -13094,7 +13094,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       <entry>
        <type>double precision</type>
       </entry>
-      <entry>No</entry>
+      <entry>Yes</entry>
       <entry>sample covariance</entry>
      </row>
 
@@ -13111,7 +13111,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       <entry>
        <type>double precision</type>
       </entry>
-      <entry>No</entry>
+      <entry>Yes</entry>
       <entry>average of the independent variable
       (<literal>sum(<replaceable class="parameter">X</replaceable>)/<replaceable class="parameter">N</replaceable></literal>)</entry>
      </row>
@@ -13129,7 +13129,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       <entry>
        <type>double precision</type>
       </entry>
-      <entry>No</entry>
+      <entry>Yes</entry>
       <entry>average of the dependent variable
       (<literal>sum(<replaceable class="parameter">Y</replaceable>)/<replaceable class="parameter">N</replaceable></literal>)</entry>
      </row>
@@ -13147,7 +13147,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       <entry>
        <type>bigint</type>
       </entry>
-      <entry>No</entry>
+      <entry>Yes</entry>
       <entry>number of input rows in which both expressions are nonnull</entry>
      </row>
 
@@ -13167,7 +13167,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       <entry>
        <type>double precision</type>
       </entry>
-      <entry>No</entry>
+      <entry>Yes</entry>
       <entry>y-intercept of the least-squares-fit linear equation
       determined by the (<replaceable
       class="parameter">X</replaceable>, <replaceable
@@ -13187,7 +13187,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       <entry>
        <type>double precision</type>
       </entry>
-      <entry>No</entry>
+      <entry>Yes</entry>
       <entry>square of the correlation coefficient</entry>
      </row>
 
@@ -13207,7 +13207,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       <entry>
        <type>double precision</type>
       </entry>
-      <entry>No</entry>
+      <entry>Yes</entry>
       <entry>slope of the least-squares-fit linear equation determined
       by the (<replaceable class="parameter">X</replaceable>,
       <replaceable class="parameter">Y</replaceable>) pairs</entry>
@@ -13226,7 +13226,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       <entry>
        <type>double precision</type>
       </entry>
-      <entry>No</entry>
+      <entry>Yes</entry>
       <entry><literal>sum(<replaceable
       class="parameter">X</replaceable>^2) - sum(<replaceable
       class="parameter">X</replaceable>)^2/<replaceable
@@ -13247,7 +13247,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       <entry>
        <type>double precision</type>
       </entry>
-      <entry>No</entry>
+      <entry>Yes</entry>
       <entry><literal>sum(<replaceable
       class="parameter">X</replaceable>*<replaceable
       class="parameter">Y</replaceable>) - sum(<replaceable
@@ -13271,7 +13271,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
       <entry>
        <type>double precision</type>
       </entry>
-      <entry>No</entry>
+      <entry>Yes</entry>
       <entry><literal>sum(<replaceable
       class="parameter">Y</replaceable>^2) - sum(<replaceable
       class="parameter">Y</replaceable>)^2/<replaceable
@@ -13298,7 +13298,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
        <type>double precision</type> for floating-point arguments,
        otherwise <type>numeric</type>
       </entry>
-      <entry>All types apart from floating-point types</entry>
+      <entry>Yes</entry>
       <entry>historical alias for <function>stddev_samp</function></entry>
      </row>
 
@@ -13322,7 +13322,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
        <type>double precision</type> for floating-point arguments,
        otherwise <type>numeric</type>
       </entry>
-      <entry>All types apart from floating-point types</entry>
+      <entry>Yes</entry>
       <entry>population standard deviation of the input values</entry>
      </row>
 
@@ -13346,7 +13346,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
        <type>double precision</type> for floating-point arguments,
        otherwise <type>numeric</type>
       </entry>
-      <entry>All types apart from floating-point types</entry>
+      <entry>Yes</entry>
       <entry>sample standard deviation of the input values</entry>
      </row>
 
@@ -13366,7 +13366,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
        <type>double precision</type> for floating-point arguments,
        otherwise <type>numeric</type>
       </entry>
-      <entry>All types apart from floating-point types</entry>
+      <entry>Yes</entry>
       <entry>historical alias for <function>var_samp</function></entry>
      </row>
 
@@ -13390,7 +13390,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
        <type>double precision</type> for floating-point arguments,
        otherwise <type>numeric</type>
       </entry>
-      <entry>All types apart from floating-point types</entry>
+      <entry>Yes</entry>
       <entry>population variance of the input values (square of the population standard deviation)</entry>
      </row>
 
@@ -13414,7 +13414,7 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
        <type>double precision</type> for floating-point arguments,
        otherwise <type>numeric</type>
       </entry>
-      <entry>All types apart from floating-point types</entry>
+      <entry>Yes</entry>
       <entry>sample variance of the input values (square of the sample standard deviation)</entry>
      </row>
     </tbody>
diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index d4e5d55..b15ec23 100644
--- a/src/backend/utils/adt/float.c
+++ b/src/backend/utils/adt/float.c
@@ -2394,6 +2394,48 @@ check_float8_array(ArrayType *transarray, const char *caller, int n)
 	return (float8 *) ARR_DATA_PTR(transarray);
 }
 
+/*
+ * float8_combine
+ *
+ * An aggregate combine function used to combine two 3 fields
+ * aggregate transition data into a single transition data.
+ * This function is used only in two stage aggregation and
+ * shouldn't be called outside aggregate context.
+ */
+Datum
+float8_combine(PG_FUNCTION_ARGS)
+{
+	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
+	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
+	float8	   *transvalues1;
+	float8	   *transvalues2;
+	float8		N,
+				sumX,
+				sumX2;
+
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	transvalues1 = check_float8_array(transarray1, "float8_combine", 3);
+	N = transvalues1[0];
+	sumX = transvalues1[1];
+	sumX2 = transvalues1[2];
+
+	transvalues2 = check_float8_array(transarray2, "float8_combine", 3);
+
+	N += transvalues2[0];
+	sumX += transvalues2[1];
+	CHECKFLOATVAL(sumX, isinf(transvalues1[1]) || isinf(transvalues2[1]), true);
+	sumX2 += transvalues1[2];
+	CHECKFLOATVAL(sumX2, isinf(transvalues1[2]) || isinf(transvalues2[1]), true);
+
+	transvalues1[0] = N;
+	transvalues1[1] = sumX;
+	transvalues1[2] = sumX2;
+
+	PG_RETURN_ARRAYTYPE_P(transarray1);
+}
+
 Datum
 float8_accum(PG_FUNCTION_ARGS)
 {
@@ -2721,6 +2763,65 @@ float8_regr_accum(PG_FUNCTION_ARGS)
 	}
 }
 
+/*
+ * float8_regr_combine
+ *
+ * An aggregate combine function used to combine two 6 fields
+ * aggregate transition data into a single transition data.
+ * This function is used only in two stage aggregation and
+ * shouldn't be called outside aggregate context.
+ */
+Datum
+float8_regr_combine(PG_FUNCTION_ARGS)
+{
+	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
+	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
+	float8	   *transvalues1;
+	float8	   *transvalues2;
+	float8		N,
+				sumX,
+				sumX2,
+				sumY,
+				sumY2,
+				sumXY;
+
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	transvalues1 = check_float8_array(transarray1, "float8_regr_combine", 6);
+	N = transvalues1[0];
+	sumX = transvalues1[1];
+	sumX2 = transvalues1[2];
+	sumY = transvalues1[3];
+	sumY2 = transvalues1[4];
+	sumXY = transvalues1[5];
+
+	transvalues2 = check_float8_array(transarray2, "float8_regr_combine", 6);
+
+	N += transvalues2[0];
+	sumX += transvalues2[1];
+	CHECKFLOATVAL(sumX, isinf(transvalues1[1]) || isinf(transvalues2[1]), true);
+	sumX2 += transvalues2[2];
+	CHECKFLOATVAL(sumX2, isinf(transvalues1[2]) || isinf(transvalues2[1]), true);
+	sumY += transvalues2[3];
+	CHECKFLOATVAL(sumY, isinf(transvalues1[3]) || isinf(transvalues2[3]), true);
+	sumY2 += transvalues2[4];
+	CHECKFLOATVAL(sumY2, isinf(transvalues1[4]) || isinf(transvalues2[3]), true);
+	sumXY += transvalues2[5];
+	CHECKFLOATVAL(sumXY, isinf(transvalues1[5]) || isinf(transvalues2[1]) ||
+				  isinf(transvalues2[3]), true);
+
+	transvalues1[0] = N;
+	transvalues1[1] = sumX;
+	transvalues1[2] = sumX2;
+	transvalues1[3] = sumY;
+	transvalues1[4] = sumY2;
+	transvalues1[5] = sumXY;
+
+	PG_RETURN_ARRAYTYPE_P(transarray1);
+}
+
+
 Datum
 float8_regr_sxx(PG_FUNCTION_ARGS)
 {
diff --git a/src/include/catalog/pg_aggregate.h b/src/include/catalog/pg_aggregate.h
index 441db30..69ecb23 100644
--- a/src/include/catalog/pg_aggregate.h
+++ b/src/include/catalog/pg_aggregate.h
@@ -133,8 +133,8 @@ DATA(insert ( 2100	n 0 int8_avg_accum	numeric_poly_avg	-	int8_avg_accum	int8_avg
 DATA(insert ( 2101	n 0 int4_avg_accum	int8_avg			-	int4_avg_accum	int4_avg_accum_inv	int8_avg			f f 0	1016	0	1016	0	"{0,0}" "{0,0}" ));
 DATA(insert ( 2102	n 0 int2_avg_accum	int8_avg			-	int2_avg_accum	int2_avg_accum_inv	int8_avg			f f 0	1016	0	1016	0	"{0,0}" "{0,0}" ));
 DATA(insert ( 2103	n 0 numeric_avg_accum numeric_avg		-	numeric_avg_accum numeric_accum_inv numeric_avg			f f 0	2281	128 2281	128 _null_ _null_ ));
-DATA(insert ( 2104	n 0 float4_accum	float8_avg			-	-				-				-						f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
-DATA(insert ( 2105	n 0 float8_accum	float8_avg			-	-				-				-						f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
+DATA(insert ( 2104	n 0 float4_accum	float8_avg			float8_combine	-				-				-					f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
+DATA(insert ( 2105	n 0 float8_accum	float8_avg			float8_combine	-				-				-					f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
 DATA(insert ( 2106	n 0 interval_accum	interval_avg		-	interval_accum	interval_accum_inv interval_avg			f f 0	1187	0	1187	0	"{0 second,0 second}" "{0 second,0 second}" ));
 
 /* sum */
@@ -201,63 +201,63 @@ DATA(insert ( 2803	n 0 int8inc			-				int8pl	int8inc			int8dec			-				f f 0		20
 DATA(insert ( 2718	n 0 int8_accum	numeric_var_pop			-	int8_accum		int8_accum_inv	numeric_var_pop			f f 0	2281	128 2281	128 _null_ _null_ ));
 DATA(insert ( 2719	n 0 int4_accum	numeric_poly_var_pop	-	int4_accum		int4_accum_inv	numeric_poly_var_pop	f f 0	2281	48	2281	48	_null_ _null_ ));
 DATA(insert ( 2720	n 0 int2_accum	numeric_poly_var_pop	-	int2_accum		int2_accum_inv	numeric_poly_var_pop	f f 0	2281	48	2281	48	_null_ _null_ ));
-DATA(insert ( 2721	n 0 float4_accum	float8_var_pop		-	-				-				-						f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
-DATA(insert ( 2722	n 0 float8_accum	float8_var_pop		-	-				-				-						f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
+DATA(insert ( 2721	n 0 float4_accum	float8_var_pop		float8_combine	-				-				-					f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
+DATA(insert ( 2722	n 0 float8_accum	float8_var_pop		float8_combine	-				-				-					f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
 DATA(insert ( 2723	n 0 numeric_accum	numeric_var_pop		-	numeric_accum numeric_accum_inv numeric_var_pop			f f 0	2281	128 2281	128 _null_ _null_ ));
 
 /* var_samp */
 DATA(insert ( 2641	n 0 int8_accum	numeric_var_samp		-	int8_accum		int8_accum_inv	numeric_var_samp		f f 0	2281	128 2281	128 _null_ _null_ ));
 DATA(insert ( 2642	n 0 int4_accum	numeric_poly_var_samp	-	int4_accum		int4_accum_inv	numeric_poly_var_samp	f f 0	2281	48	2281	48	_null_ _null_ ));
 DATA(insert ( 2643	n 0 int2_accum	numeric_poly_var_samp	-	int2_accum		int2_accum_inv	numeric_poly_var_samp	f f 0	2281	48	2281	48	_null_ _null_ ));
-DATA(insert ( 2644	n 0 float4_accum	float8_var_samp		-	-				-				-						f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
-DATA(insert ( 2645	n 0 float8_accum	float8_var_samp		-	-				-				-						f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
+DATA(insert ( 2644	n 0 float4_accum	float8_var_samp		float8_combine	-				-				-					f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
+DATA(insert ( 2645	n 0 float8_accum	float8_var_samp		float8_combine	-				-				-					f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
 DATA(insert ( 2646	n 0 numeric_accum	numeric_var_samp	-	numeric_accum	numeric_accum_inv numeric_var_samp		f f 0	2281	128 2281	128 _null_ _null_ ));
 
 /* variance: historical Postgres syntax for var_samp */
 DATA(insert ( 2148	n 0 int8_accum	numeric_var_samp		-	int8_accum		int8_accum_inv	numeric_var_samp		f f 0	2281	128 2281	128 _null_ _null_ ));
 DATA(insert ( 2149	n 0 int4_accum	numeric_poly_var_samp	-	int4_accum		int4_accum_inv	numeric_poly_var_samp	f f 0	2281	48	2281	48	_null_ _null_ ));
 DATA(insert ( 2150	n 0 int2_accum	numeric_poly_var_samp	-	int2_accum		int2_accum_inv	numeric_poly_var_samp	f f 0	2281	48	2281	48	_null_ _null_ ));
-DATA(insert ( 2151	n 0 float4_accum	float8_var_samp		-	-				-				-						f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
-DATA(insert ( 2152	n 0 float8_accum	float8_var_samp		-	-				-				-						f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
+DATA(insert ( 2151	n 0 float4_accum	float8_var_samp		float8_combine	-				-				-					f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
+DATA(insert ( 2152	n 0 float8_accum	float8_var_samp		float8_combine	-				-				-					f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
 DATA(insert ( 2153	n 0 numeric_accum	numeric_var_samp	-	numeric_accum numeric_accum_inv numeric_var_samp		f f 0	2281	128 2281	128 _null_ _null_ ));
 
 /* stddev_pop */
 DATA(insert ( 2724	n 0 int8_accum	numeric_stddev_pop		-	int8_accum	int8_accum_inv	numeric_stddev_pop		f f 0	2281	128	2281	128 _null_ _null_ ));
 DATA(insert ( 2725	n 0 int4_accum	numeric_poly_stddev_pop	-	int4_accum	int4_accum_inv	numeric_poly_stddev_pop	f f 0	2281	48	2281	48	_null_ _null_ ));
 DATA(insert ( 2726	n 0 int2_accum	numeric_poly_stddev_pop	-	int2_accum	int2_accum_inv	numeric_poly_stddev_pop	f f 0	2281	48	2281	48	_null_ _null_ ));
-DATA(insert ( 2727	n 0 float4_accum	float8_stddev_pop	-	-				-				-					f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
-DATA(insert ( 2728	n 0 float8_accum	float8_stddev_pop	-	-				-				-					f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
+DATA(insert ( 2727	n 0 float4_accum	float8_stddev_pop	float8_combine	-				-				-				f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
+DATA(insert ( 2728	n 0 float8_accum	float8_stddev_pop	float8_combine	-				-				-				f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
 DATA(insert ( 2729	n 0 numeric_accum	numeric_stddev_pop	-	numeric_accum numeric_accum_inv numeric_stddev_pop	f f 0	2281	128 2281	128 _null_ _null_ ));
 
 /* stddev_samp */
 DATA(insert ( 2712	n 0 int8_accum	numeric_stddev_samp			-	int8_accum	int8_accum_inv	numeric_stddev_samp			f f 0	2281	128 2281	128 _null_ _null_ ));
 DATA(insert ( 2713	n 0 int4_accum	numeric_poly_stddev_samp	-	int4_accum	int4_accum_inv	numeric_poly_stddev_samp	f f 0	2281	48	2281	48	_null_ _null_ ));
 DATA(insert ( 2714	n 0 int2_accum	numeric_poly_stddev_samp	-	int2_accum	int2_accum_inv	numeric_poly_stddev_samp	f f 0	2281	48	2281	48	_null_ _null_ ));
-DATA(insert ( 2715	n 0 float4_accum	float8_stddev_samp		-	-				-				-						f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
-DATA(insert ( 2716	n 0 float8_accum	float8_stddev_samp		-	-				-				-						f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
+DATA(insert ( 2715	n 0 float4_accum	float8_stddev_samp		float8_combine	-				-				-					f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
+DATA(insert ( 2716	n 0 float8_accum	float8_stddev_samp		float8_combine	-				-				-					f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
 DATA(insert ( 2717	n 0 numeric_accum	numeric_stddev_samp		-	numeric_accum numeric_accum_inv numeric_stddev_samp		f f 0	2281	128 2281	128 _null_ _null_ ));
 
 /* stddev: historical Postgres syntax for stddev_samp */
 DATA(insert ( 2154	n 0 int8_accum	numeric_stddev_samp			-	int8_accum		int8_accum_inv	numeric_stddev_samp			f f 0	2281	128 2281	128 _null_ _null_ ));
 DATA(insert ( 2155	n 0 int4_accum	numeric_poly_stddev_samp	-	int4_accum		int4_accum_inv	numeric_poly_stddev_samp	f f 0	2281	48	2281	48	_null_ _null_ ));
 DATA(insert ( 2156	n 0 int2_accum	numeric_poly_stddev_samp	-	int2_accum		int2_accum_inv	numeric_poly_stddev_samp	f f 0	2281	48	2281	48	_null_ _null_ ));
-DATA(insert ( 2157	n 0 float4_accum	float8_stddev_samp		-	-				-				-							f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
-DATA(insert ( 2158	n 0 float8_accum	float8_stddev_samp		-	-				-				-							f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
+DATA(insert ( 2157	n 0 float4_accum	float8_stddev_samp		float8_combine	-				-				-						f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
+DATA(insert ( 2158	n 0 float8_accum	float8_stddev_samp		float8_combine	-				-				-						f f 0	1022	0	0		0	"{0,0,0}" _null_ ));
 DATA(insert ( 2159	n 0 numeric_accum	numeric_stddev_samp		-	numeric_accum	numeric_accum_inv numeric_stddev_samp		f f 0	2281	128 2281	128 _null_ _null_ ));
 
 /* SQL2003 binary regression aggregates */
-DATA(insert ( 2818	n 0 int8inc_float8_float8	-					-	-				-				-			f f 0	20		0	0		0	"0" _null_ ));
-DATA(insert ( 2819	n 0 float8_regr_accum	float8_regr_sxx			-	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
-DATA(insert ( 2820	n 0 float8_regr_accum	float8_regr_syy			-	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
-DATA(insert ( 2821	n 0 float8_regr_accum	float8_regr_sxy			-	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
-DATA(insert ( 2822	n 0 float8_regr_accum	float8_regr_avgx		-	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
-DATA(insert ( 2823	n 0 float8_regr_accum	float8_regr_avgy		-	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
-DATA(insert ( 2824	n 0 float8_regr_accum	float8_regr_r2			-	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
-DATA(insert ( 2825	n 0 float8_regr_accum	float8_regr_slope		-	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
-DATA(insert ( 2826	n 0 float8_regr_accum	float8_regr_intercept	-	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
-DATA(insert ( 2827	n 0 float8_regr_accum	float8_covar_pop		-	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
-DATA(insert ( 2828	n 0 float8_regr_accum	float8_covar_samp		-	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
-DATA(insert ( 2829	n 0 float8_regr_accum	float8_corr				-	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
+DATA(insert ( 2818	n 0 int8inc_float8_float8	-					int8pl			-				-				-			f f 0	20		0	0		0	"0" _null_ ));
+DATA(insert ( 2819	n 0 float8_regr_accum	float8_regr_sxx			float8_regr_combine	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
+DATA(insert ( 2820	n 0 float8_regr_accum	float8_regr_syy			float8_regr_combine	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
+DATA(insert ( 2821	n 0 float8_regr_accum	float8_regr_sxy			float8_regr_combine	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
+DATA(insert ( 2822	n 0 float8_regr_accum	float8_regr_avgx		float8_regr_combine	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
+DATA(insert ( 2823	n 0 float8_regr_accum	float8_regr_avgy		float8_regr_combine	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
+DATA(insert ( 2824	n 0 float8_regr_accum	float8_regr_r2			float8_regr_combine	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
+DATA(insert ( 2825	n 0 float8_regr_accum	float8_regr_slope		float8_regr_combine	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
+DATA(insert ( 2826	n 0 float8_regr_accum	float8_regr_intercept	float8_regr_combine	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
+DATA(insert ( 2827	n 0 float8_regr_accum	float8_covar_pop		float8_regr_combine	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
+DATA(insert ( 2828	n 0 float8_regr_accum	float8_covar_samp		float8_regr_combine	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
+DATA(insert ( 2829	n 0 float8_regr_accum	float8_corr				float8_regr_combine	-				-				-			f f 0	1022	0	0		0	"{0,0,0,0,0,0}" _null_ ));
 
 /* boolean-and and boolean-or */
 DATA(insert ( 2517	n 0 booland_statefunc	-	-	bool_accum	bool_accum_inv	bool_alltrue	f f 58	16		0	2281	16	_null_ _null_ ));
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index ceb8129..7e00908 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -400,6 +400,8 @@ DATA(insert OID = 220 (  float8um		   PGNSP PGUID 12 1 0 0 0 f f f f t f i s 1 0
 DATA(insert OID = 221 (  float8abs		   PGNSP PGUID 12 1 0 0 0 f f f f t f i s 1 0 701 "701" _null_ _null_ _null_ _null_ _null_	float8abs _null_ _null_ _null_ ));
 DATA(insert OID = 222 (  float8_accum	   PGNSP PGUID 12 1 0 0 0 f f f f t f i s 2 0 1022 "1022 701" _null_ _null_ _null_ _null_ _null_ float8_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
+DATA(insert OID = 276 (  float8_combine		   PGNSP PGUID 12 1 0 0 0 f f f f t f i s 2 0 1022 "1022 1022" _null_ _null_ _null_ _null_ _null_ float8_combine _null_ _null_ _null_ ));
+DESCR("aggregate combine function");
 DATA(insert OID = 223 (  float8larger	   PGNSP PGUID 12 1 0 0 0 f f f f t f i s 2 0 701 "701 701" _null_ _null_ _null_ _null_ _null_	float8larger _null_ _null_ _null_ ));
 DESCR("larger of two");
 DATA(insert OID = 224 (  float8smaller	   PGNSP PGUID 12 1 0 0 0 f f f f t f i s 2 0 701 "701 701" _null_ _null_ _null_ _null_ _null_	float8smaller _null_ _null_ _null_ ));
@@ -2514,6 +2516,8 @@ DATA(insert OID = 2805 (  int8inc_float8_float8		PGNSP PGUID 12 1 0 0 0 f f f f
 DESCR("aggregate transition function");
 DATA(insert OID = 2806 (  float8_regr_accum			PGNSP PGUID 12 1 0 0 0 f f f f t f i s 3 0 1022 "1022 701 701" _null_ _null_ _null_ _null_ _null_ float8_regr_accum _null_ _null_ _null_ ));
 DESCR("aggregate transition function");
+DATA(insert OID = 3324 (  float8_regr_combine			PGNSP PGUID 12 1 0 0 0 f f f f t f i s 2 0 1022 "1022 1022" _null_ _null_ _null_ _null_ _null_ float8_regr_combine _null_ _null_ _null_ ));
+DESCR("aggregate combine function");
 DATA(insert OID = 2807 (  float8_regr_sxx			PGNSP PGUID 12 1 0 0 0 f f f f t f i s 1 0 701 "1022" _null_ _null_ _null_ _null_ _null_ float8_regr_sxx _null_ _null_ _null_ ));
 DESCR("aggregate final function");
 DATA(insert OID = 2808 (  float8_regr_syy			PGNSP PGUID 12 1 0 0 0 f f f f t f i s 1 0 701 "1022" _null_ _null_ _null_ _null_ _null_ float8_regr_syy _null_ _null_ _null_ ));
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 59a00bb..b9c7894 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -424,6 +424,7 @@ extern Datum dpi(PG_FUNCTION_ARGS);
 extern Datum radians(PG_FUNCTION_ARGS);
 extern Datum drandom(PG_FUNCTION_ARGS);
 extern Datum setseed(PG_FUNCTION_ARGS);
+extern Datum float8_combine(PG_FUNCTION_ARGS);
 extern Datum float8_accum(PG_FUNCTION_ARGS);
 extern Datum float4_accum(PG_FUNCTION_ARGS);
 extern Datum float8_avg(PG_FUNCTION_ARGS);
@@ -432,6 +433,7 @@ extern Datum float8_var_samp(PG_FUNCTION_ARGS);
 extern Datum float8_stddev_pop(PG_FUNCTION_ARGS);
 extern Datum float8_stddev_samp(PG_FUNCTION_ARGS);
 extern Datum float8_regr_accum(PG_FUNCTION_ARGS);
+extern Datum float8_regr_combine(PG_FUNCTION_ARGS);
 extern Datum float8_regr_sxx(PG_FUNCTION_ARGS);
 extern Datum float8_regr_syy(PG_FUNCTION_ARGS);
 extern Datum float8_regr_sxy(PG_FUNCTION_ARGS);
