Support ordered-set (WITHIN GROUP) aggregates.

This patch introduces generic support for ordered-set and hypothetical-set
aggregate functions, as well as implementations of the instances defined in
SQL:2008 (percentile_cont(), percentile_disc(), rank(), dense_rank(),
percent_rank(), cume_dist()).  We also added mode() though it is not in the
spec, as well as versions of percentile_cont() and percentile_disc() that
can compute multiple percentile values in one pass over the data.

Unlike the original submission, this patch puts full control of the sorting
process in the hands of the aggregate's support functions.  To allow the
support functions to find out how they're supposed to sort, a new API
function AggGetAggref() is added to nodeAgg.c.  This allows retrieval of
the aggregate call's Aggref node, which may have other uses beyond the
immediate need.  There is also support for ordered-set aggregates to
install cleanup callback functions, so that they can be sure that
infrastructure such as tuplesort objects gets cleaned up.

In passing, make some fixes in the recently-added support for variadic
aggregates, and make some editorial adjustments in the recent FILTER
additions for aggregates.  Also, simplify use of IsBinaryCoercible() by
allowing it to succeed whenever the target type is ANY or ANYELEMENT.
It was inconsistent that it dealt with other polymorphic target types
but not these.

Atri Sharma and Andrew Gierth; reviewed by Pavel Stehule and Vik Fearing,
and rather heavily editorialized upon by Tom Lane

17 files changed, 296 insertions, 150 deletions

diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index b7610e8c3f8..e8b60bda7e1 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201312131
+#define CATALOG_VERSION_NO	201312231
 
 #endif
diff --git a/src/include/catalog/pg_aggregate.h b/src/include/catalog/pg_aggregate.h
index 034456a315d..f0eaf60a09b 100644
--- a/src/include/catalog/pg_aggregate.h
+++ b/src/include/catalog/pg_aggregate.h
@@ -28,6 +28,8 @@
  *		cpp turns this into typedef struct FormData_pg_aggregate
  *
  *	aggfnoid			pg_proc OID of the aggregate itself
+ *	aggkind				aggregate kind, see AGGKIND_ categories below
+ *	aggnumdirectargs	number of arguments that are "direct" arguments
  *	aggtransfn			transition function
  *	aggfinalfn			final function (0 if none)
  *	aggsortop			associated sort operator (0 if none)
@@ -41,6 +43,8 @@
 CATALOG(pg_aggregate,2600) BKI_WITHOUT_OIDS
 {
 	regproc		aggfnoid;
+	char		aggkind;
+	int16		aggnumdirectargs;
 	regproc		aggtransfn;
 	regproc		aggfinalfn;
 	Oid			aggsortop;
@@ -64,14 +68,31 @@ typedef FormData_pg_aggregate *Form_pg_aggregate;
  * ----------------
  */
 
-#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
+#define Natts_pg_aggregate					9
+#define Anum_pg_aggregate_aggfnoid			1
+#define Anum_pg_aggregate_aggkind			2
+#define Anum_pg_aggregate_aggnumdirectargs	3
+#define Anum_pg_aggregate_aggtransfn		4
+#define Anum_pg_aggregate_aggfinalfn		5
+#define Anum_pg_aggregate_aggsortop			6
+#define Anum_pg_aggregate_aggtranstype		7
+#define Anum_pg_aggregate_aggtransspace		8
+#define Anum_pg_aggregate_agginitval		9
+
+/*
+ * Symbolic values for aggkind column.	We distinguish normal aggregates
+ * from ordered-set aggregates (which have two sets of arguments, namely
+ * direct and aggregated arguments) and from hypothetical-set aggregates
+ * (which are a subclass of ordered-set aggregates in which the last
+ * direct arguments have to match up in number and datatypes with the
+ * aggregated arguments).
+ */
+#define AGGKIND_NORMAL			'n'
+#define AGGKIND_ORDERED_SET		'o'
+#define AGGKIND_HYPOTHETICAL	'h'
+
+/* Use this macro to test for "ordered-set agg including hypothetical case" */
+#define AGGKIND_IS_ORDERED_SET(kind)  ((kind) != AGGKIND_NORMAL)
 
 
 /* ----------------
@@ -80,175 +101,192 @@ typedef FormData_pg_aggregate *Form_pg_aggregate;
  */
 
 /* 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}" ));
+DATA(insert ( 2100	n 0 int8_avg_accum	numeric_avg		0	2281	128 _null_ ));
+DATA(insert ( 2101	n 0 int4_avg_accum	int8_avg		0	1016	0	"{0,0}" ));
+DATA(insert ( 2102	n 0 int2_avg_accum	int8_avg		0	1016	0	"{0,0}" ));
+DATA(insert ( 2103	n 0 numeric_avg_accum	numeric_avg 0	2281	128 _null_ ));
+DATA(insert ( 2104	n 0 float4_accum	float8_avg		0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2105	n 0 float8_accum	float8_avg		0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2106	n 0 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_ ));
+DATA(insert ( 2107	n 0 int8_avg_accum	numeric_sum		0	2281	128 _null_ ));
+DATA(insert ( 2108	n 0 int4_sum		-				0	20		0	_null_ ));
+DATA(insert ( 2109	n 0 int2_sum		-				0	20		0	_null_ ));
+DATA(insert ( 2110	n 0 float4pl		-				0	700		0	_null_ ));
+DATA(insert ( 2111	n 0 float8pl		-				0	701		0	_null_ ));
+DATA(insert ( 2112	n 0 cash_pl			-				0	790		0	_null_ ));
+DATA(insert ( 2113	n 0 interval_pl		-				0	1186	0	_null_ ));
+DATA(insert ( 2114	n 0 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_ ));
+DATA(insert ( 2115	n 0 int8larger		-				413		20		0	_null_ ));
+DATA(insert ( 2116	n 0 int4larger		-				521		23		0	_null_ ));
+DATA(insert ( 2117	n 0 int2larger		-				520		21		0	_null_ ));
+DATA(insert ( 2118	n 0 oidlarger		-				610		26		0	_null_ ));
+DATA(insert ( 2119	n 0 float4larger	-				623		700		0	_null_ ));
+DATA(insert ( 2120	n 0 float8larger	-				674		701		0	_null_ ));
+DATA(insert ( 2121	n 0 int4larger		-				563		702		0	_null_ ));
+DATA(insert ( 2122	n 0 date_larger		-				1097	1082	0	_null_ ));
+DATA(insert ( 2123	n 0 time_larger		-				1112	1083	0	_null_ ));
+DATA(insert ( 2124	n 0 timetz_larger	-				1554	1266	0	_null_ ));
+DATA(insert ( 2125	n 0 cashlarger		-				903		790		0	_null_ ));
+DATA(insert ( 2126	n 0 timestamp_larger	-			2064	1114	0	_null_ ));
+DATA(insert ( 2127	n 0 timestamptz_larger	-			1324	1184	0	_null_ ));
+DATA(insert ( 2128	n 0 interval_larger -				1334	1186	0	_null_ ));
+DATA(insert ( 2129	n 0 text_larger		-				666		25		0	_null_ ));
+DATA(insert ( 2130	n 0 numeric_larger	-				1756	1700	0	_null_ ));
+DATA(insert ( 2050	n 0 array_larger	-				1073	2277	0	_null_ ));
+DATA(insert ( 2244	n 0 bpchar_larger	-				1060	1042	0	_null_ ));
+DATA(insert ( 2797	n 0 tidlarger		-				2800	27		0	_null_ ));
+DATA(insert ( 3526	n 0 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_ ));
+DATA(insert ( 2131	n 0 int8smaller		-				412		20		0	_null_ ));
+DATA(insert ( 2132	n 0 int4smaller		-				97		23		0	_null_ ));
+DATA(insert ( 2133	n 0 int2smaller		-				95		21		0	_null_ ));
+DATA(insert ( 2134	n 0 oidsmaller		-				609		26		0	_null_ ));
+DATA(insert ( 2135	n 0 float4smaller	-				622		700		0	_null_ ));
+DATA(insert ( 2136	n 0 float8smaller	-				672		701		0	_null_ ));
+DATA(insert ( 2137	n 0 int4smaller		-				562		702		0	_null_ ));
+DATA(insert ( 2138	n 0 date_smaller	-				1095	1082	0	_null_ ));
+DATA(insert ( 2139	n 0 time_smaller	-				1110	1083	0	_null_ ));
+DATA(insert ( 2140	n 0 timetz_smaller	-				1552	1266	0	_null_ ));
+DATA(insert ( 2141	n 0 cashsmaller		-				902		790		0	_null_ ));
+DATA(insert ( 2142	n 0 timestamp_smaller	-			2062	1114	0	_null_ ));
+DATA(insert ( 2143	n 0 timestamptz_smaller -			1322	1184	0	_null_ ));
+DATA(insert ( 2144	n 0 interval_smaller	-			1332	1186	0	_null_ ));
+DATA(insert ( 2145	n 0 text_smaller	-				664		25		0	_null_ ));
+DATA(insert ( 2146	n 0 numeric_smaller -				1754	1700	0	_null_ ));
+DATA(insert ( 2051	n 0 array_smaller	-				1072	2277	0	_null_ ));
+DATA(insert ( 2245	n 0 bpchar_smaller	-				1058	1042	0	_null_ ));
+DATA(insert ( 2798	n 0 tidsmaller		-				2799	27		0	_null_ ));
+DATA(insert ( 3527	n 0 enum_smaller	-				3518	3500	0	_null_ ));
 
 /* count */
-DATA(insert ( 2147	int8inc_any		-				0		20		0	"0" ));
-DATA(insert ( 2803	int8inc			-				0		20		0	"0" ));
+DATA(insert ( 2147	n 0 int8inc_any		-				0		20		0	"0" ));
+DATA(insert ( 2803	n 0 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_ ));
+DATA(insert ( 2718	n 0 int8_accum	numeric_var_pop 0	2281	128 _null_ ));
+DATA(insert ( 2719	n 0 int4_accum	numeric_var_pop 0	2281	128 _null_ ));
+DATA(insert ( 2720	n 0 int2_accum	numeric_var_pop 0	2281	128 _null_ ));
+DATA(insert ( 2721	n 0 float4_accum	float8_var_pop 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2722	n 0 float8_accum	float8_var_pop 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2723	n 0 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_ ));
+DATA(insert ( 2641	n 0 int8_accum	numeric_var_samp	0	2281	128 _null_ ));
+DATA(insert ( 2642	n 0 int4_accum	numeric_var_samp	0	2281	128 _null_ ));
+DATA(insert ( 2643	n 0 int2_accum	numeric_var_samp	0	2281	128 _null_ ));
+DATA(insert ( 2644	n 0 float4_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2645	n 0 float8_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2646	n 0 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_ ));
+DATA(insert ( 2148	n 0 int8_accum	numeric_var_samp	0	2281	128 _null_ ));
+DATA(insert ( 2149	n 0 int4_accum	numeric_var_samp	0	2281	128 _null_ ));
+DATA(insert ( 2150	n 0 int2_accum	numeric_var_samp	0	2281	128 _null_ ));
+DATA(insert ( 2151	n 0 float4_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2152	n 0 float8_accum	float8_var_samp 0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2153	n 0 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_ ));
+DATA(insert ( 2724	n 0 int8_accum	numeric_stddev_pop		0	2281	128 _null_ ));
+DATA(insert ( 2725	n 0 int4_accum	numeric_stddev_pop		0	2281	128 _null_ ));
+DATA(insert ( 2726	n 0 int2_accum	numeric_stddev_pop		0	2281	128 _null_ ));
+DATA(insert ( 2727	n 0 float4_accum	float8_stddev_pop	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2728	n 0 float8_accum	float8_stddev_pop	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2729	n 0 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_ ));
+DATA(insert ( 2712	n 0 int8_accum	numeric_stddev_samp		0	2281	128 _null_ ));
+DATA(insert ( 2713	n 0 int4_accum	numeric_stddev_samp		0	2281	128 _null_ ));
+DATA(insert ( 2714	n 0 int2_accum	numeric_stddev_samp		0	2281	128 _null_ ));
+DATA(insert ( 2715	n 0 float4_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2716	n 0 float8_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2717	n 0 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_ ));
+DATA(insert ( 2154	n 0 int8_accum	numeric_stddev_samp		0	2281	128 _null_ ));
+DATA(insert ( 2155	n 0 int4_accum	numeric_stddev_samp		0	2281	128 _null_ ));
+DATA(insert ( 2156	n 0 int2_accum	numeric_stddev_samp		0	2281	128 _null_ ));
+DATA(insert ( 2157	n 0 float4_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2158	n 0 float8_accum	float8_stddev_samp	0	1022	0	"{0,0,0}" ));
+DATA(insert ( 2159	n 0 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}" ));
+DATA(insert ( 2818	n 0 int8inc_float8_float8		-				0	20		0	"0" ));
+DATA(insert ( 2819	n 0 float8_regr_accum	float8_regr_sxx			0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2820	n 0 float8_regr_accum	float8_regr_syy			0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2821	n 0 float8_regr_accum	float8_regr_sxy			0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2822	n 0 float8_regr_accum	float8_regr_avgx		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2823	n 0 float8_regr_accum	float8_regr_avgy		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2824	n 0 float8_regr_accum	float8_regr_r2			0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2825	n 0 float8_regr_accum	float8_regr_slope		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2826	n 0 float8_regr_accum	float8_regr_intercept	0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2827	n 0 float8_regr_accum	float8_covar_pop		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2828	n 0 float8_regr_accum	float8_covar_samp		0	1022	0	"{0,0,0,0,0,0}" ));
+DATA(insert ( 2829	n 0 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_ ));
+DATA(insert ( 2517	n 0 booland_statefunc	-			58	16		0	_null_ ));
+DATA(insert ( 2518	n 0 boolor_statefunc	-			59	16		0	_null_ ));
+DATA(insert ( 2519	n 0 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_ ));
+DATA(insert ( 2236	n 0 int2and		-					0	21		0	_null_ ));
+DATA(insert ( 2237	n 0 int2or		-					0	21		0	_null_ ));
+DATA(insert ( 2238	n 0 int4and		-					0	23		0	_null_ ));
+DATA(insert ( 2239	n 0 int4or		-					0	23		0	_null_ ));
+DATA(insert ( 2240	n 0 int8and		-					0	20		0	_null_ ));
+DATA(insert ( 2241	n 0 int8or		-					0	20		0	_null_ ));
+DATA(insert ( 2242	n 0 bitand		-					0	1560	0	_null_ ));
+DATA(insert ( 2243	n 0 bitor		-					0	1560	0	_null_ ));
 
 /* xml */
-DATA(insert ( 2901 xmlconcat2	  -					0	142		0	_null_ ));
+DATA(insert ( 2901	n 0 xmlconcat2	-					0	142		0	_null_ ));
 
 /* array */
-DATA(insert ( 2335	array_agg_transfn	array_agg_finalfn	0	2281	0	_null_ ));
+DATA(insert ( 2335	n 0 array_agg_transfn	array_agg_finalfn	0	2281	0	_null_ ));
 
 /* text */
-DATA(insert ( 3538	string_agg_transfn	string_agg_finalfn	0	2281	0	_null_ ));
+DATA(insert ( 3538	n 0 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_ ));
+DATA(insert ( 3545	n 0 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_ ));
+DATA(insert ( 3175	n 0 json_agg_transfn	json_agg_finalfn	0	2281	0	_null_ ));
+
+/* ordered-set and hypothetical-set aggregates */
+DATA(insert ( 3972	o 1 ordered_set_transition			percentile_disc_final					0	2281	0	_null_ ));
+DATA(insert ( 3974	o 1 ordered_set_transition			percentile_cont_float8_final			0	2281	0	_null_ ));
+DATA(insert ( 3976	o 1 ordered_set_transition			percentile_cont_interval_final			0	2281	0	_null_ ));
+DATA(insert ( 3978	o 1 ordered_set_transition			percentile_disc_multi_final				0	2281	0	_null_ ));
+DATA(insert ( 3980	o 1 ordered_set_transition			percentile_cont_float8_multi_final		0	2281	0	_null_ ));
+DATA(insert ( 3982	o 1 ordered_set_transition			percentile_cont_interval_multi_final	0	2281	0	_null_ ));
+DATA(insert ( 3984	o 0 ordered_set_transition			mode_final								0	2281	0	_null_ ));
+DATA(insert ( 3986	h 1 ordered_set_transition_multi	rank_final								0	2281	0	_null_ ));
+DATA(insert ( 3988	h 1 ordered_set_transition_multi	percent_rank_final						0	2281	0	_null_ ));
+DATA(insert ( 3990	h 1 ordered_set_transition_multi	cume_dist_final							0	2281	0	_null_ ));
+DATA(insert ( 3992	h 1 ordered_set_transition_multi	dense_rank_final						0	2281	0	_null_ ));
+
 
 /*
  * prototypes for functions in pg_aggregate.c
  */
 extern Oid AggregateCreate(const char *aggName,
 				Oid aggNamespace,
+				char aggKind,
 				int numArgs,
+				int numDirectArgs,
 				oidvector *parameterTypes,
 				Datum allParameterTypes,
 				Datum parameterModes,
 				Datum parameterNames,
 				List *parameterDefaults,
+				Oid variadicArgType,
 				List *aggtransfnName,
 				List *aggfinalfnName,
 				List *aggsortopName,
diff --git a/src/include/catalog/pg_operator.h b/src/include/catalog/pg_operator.h
index 78efaa5f23e..a49cfdbdded 100644
--- a/src/include/catalog/pg_operator.h
+++ b/src/include/catalog/pg_operator.h
@@ -130,6 +130,7 @@ DATA(insert OID =  96 ( "="		   PGNSP PGUID b t t	23	23	16	96 518 int4eq eqsel e
 DESCR("equal");
 DATA(insert OID =  97 ( "<"		   PGNSP PGUID b f f	23	23	16 521 525 int4lt scalarltsel scalarltjoinsel ));
 DESCR("less than");
+#define Int4LessOperator	97
 DATA(insert OID =  98 ( "="		   PGNSP PGUID b t t	25	25	16	98 531 texteq eqsel eqjoinsel ));
 DESCR("equal");
 #define TextEqualOperator	98
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 0117500a8a6..05d7ba54072 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -4756,10 +4756,65 @@ DESCR("SP-GiST support for quad tree over range");
 DATA(insert OID = 3473 (  spg_range_quad_leaf_consistent	PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "2281 2281" _null_ _null_ _null_ _null_  spg_range_quad_leaf_consistent _null_ _null_ _null_ ));
 DESCR("SP-GiST support for quad tree over range");
 
-
 /* event triggers */
 DATA(insert OID = 3566 (  pg_event_trigger_dropped_objects		PGNSP PGUID 12 10 100 0 0 f f f f t t s 0 0 2249 "" "{26,26,23,25,25,25,25}" "{o,o,o,o,o,o,o}" "{classid, objid, objsubid, object_type, schema_name, object_name, object_identity}" _null_ pg_event_trigger_dropped_objects _null_ _null_ _null_ ));
 DESCR("list objects dropped by the current command");
+
+/* generic transition functions for ordered-set aggregates */
+DATA(insert OID = 3970 ( ordered_set_transition			PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2281 "2281 2276" _null_ _null_ _null_ _null_ ordered_set_transition _null_ _null_ _null_ ));
+DESCR("aggregate transition function");
+DATA(insert OID = 3971 ( ordered_set_transition_multi	PGNSP PGUID 12 1 0 2276 0 f f f f f f i 2 0 2281 "2281 2276" "{2281,2276}" "{i,v}" _null_ _null_ ordered_set_transition_multi _null_ _null_ _null_ ));
+DESCR("aggregate transition function");
+
+/* inverse distribution aggregates (and their support functions) */
+DATA(insert OID = 3972 ( percentile_disc		PGNSP PGUID 12 1 0 0 0 t f f f f f i 2 0 2283 "701 2283" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+DESCR("discrete percentile");
+DATA(insert OID = 3973 ( percentile_disc_final	PGNSP PGUID 12 1 0 0 0 f f f f f f i 3 0 2283 "2281 701 2283" _null_ _null_ _null_ _null_ percentile_disc_final _null_ _null_ _null_ ));
+DESCR("aggregate final function");
+DATA(insert OID = 3974 ( percentile_cont		PGNSP PGUID 12 1 0 0 0 t f f f f f i 2 0 701 "701 701" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+DESCR("continuous distribution percentile");
+DATA(insert OID = 3975 ( percentile_cont_float8_final	PGNSP PGUID 12 1 0 0 0 f f f f f f i 3 0 701 "2281 701 701" _null_ _null_ _null_ _null_ percentile_cont_float8_final _null_ _null_ _null_ ));
+DESCR("aggregate final function");
+DATA(insert OID = 3976 ( percentile_cont		PGNSP PGUID 12 1 0 0 0 t f f f f f i 2 0 1186 "701 1186" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+DESCR("continuous distribution percentile");
+DATA(insert OID = 3977 ( percentile_cont_interval_final PGNSP PGUID 12 1 0 0 0 f f f f f f i 3 0 1186 "2281 701 1186" _null_ _null_ _null_ _null_ percentile_cont_interval_final _null_ _null_ _null_ ));
+DESCR("aggregate final function");
+DATA(insert OID = 3978 ( percentile_disc		PGNSP PGUID 12 1 0 0 0 t f f f f f i 2 0 2277 "1022 2283" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+DESCR("multiple discrete percentiles");
+DATA(insert OID = 3979 ( percentile_disc_multi_final	PGNSP PGUID 12 1 0 0 0 f f f f f f i 3 0 2277 "2281 1022 2283" _null_ _null_ _null_ _null_ percentile_disc_multi_final _null_ _null_ _null_ ));
+DESCR("aggregate final function");
+DATA(insert OID = 3980 ( percentile_cont		PGNSP PGUID 12 1 0 0 0 t f f f f f i 2 0 1022 "1022 701" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+DESCR("multiple continuous percentiles");
+DATA(insert OID = 3981 ( percentile_cont_float8_multi_final PGNSP PGUID 12 1 0 0 0 f f f f f f i 3 0 1022 "2281 1022 701" _null_ _null_ _null_ _null_ percentile_cont_float8_multi_final _null_ _null_ _null_ ));
+DESCR("aggregate final function");
+DATA(insert OID = 3982 ( percentile_cont		PGNSP PGUID 12 1 0 0 0 t f f f f f i 2 0 1187 "1022 1186" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+DESCR("multiple continuous percentiles");
+DATA(insert OID = 3983 ( percentile_cont_interval_multi_final	PGNSP PGUID 12 1 0 0 0 f f f f f f i 3 0 1187 "2281 1022 1186" _null_ _null_ _null_ _null_ percentile_cont_interval_multi_final _null_ _null_ _null_ ));
+DESCR("aggregate final function");
+DATA(insert OID = 3984 ( mode					PGNSP PGUID 12 1 0 0 0 t f f f f f i 1 0 2283 "2283" _null_ _null_ _null_ _null_	aggregate_dummy _null_ _null_ _null_ ));
+DESCR("most common value");
+DATA(insert OID = 3985 ( mode_final				PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 2283 "2281 2283" _null_ _null_ _null_ _null_	mode_final _null_ _null_ _null_ ));
+DESCR("aggregate final function");
+
+/* hypothetical-set aggregates (and their support functions) */
+DATA(insert OID = 3986 ( rank				PGNSP PGUID 12 1 0 2276 0 t f f f f f i 1 0 20 "2276" "{2276}" "{v}" _null_ _null_	aggregate_dummy _null_ _null_ _null_ ));
+DESCR("rank of hypothetical row");
+DATA(insert OID = 3987 ( rank_final			PGNSP PGUID 12 1 0 2276 0 f f f f f f i 2 0 20 "2281 2276" "{2281,2276}" "{i,v}" _null_ _null_	hypothetical_rank_final _null_ _null_ _null_ ));
+DESCR("aggregate final function");
+DATA(insert OID = 3988 ( percent_rank		PGNSP PGUID 12 1 0 2276 0 t f f f f f i 1 0 701 "2276" "{2276}" "{v}" _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+DESCR("fractional rank of hypothetical row");
+DATA(insert OID = 3989 ( percent_rank_final PGNSP PGUID 12 1 0 2276 0 f f f f f f i 2 0 701 "2281 2276" "{2281,2276}" "{i,v}" _null_ _null_ hypothetical_percent_rank_final _null_ _null_ _null_ ));
+DESCR("aggregate final function");
+DATA(insert OID = 3990 ( cume_dist			PGNSP PGUID 12 1 0 2276 0 t f f f f f i 1 0 701 "2276" "{2276}" "{v}" _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+DESCR("cumulative distribution of hypothetical row");
+DATA(insert OID = 3991 ( cume_dist_final	PGNSP PGUID 12 1 0 2276 0 f f f f f f i 2 0 701 "2281 2276" "{2281,2276}" "{i,v}" _null_ _null_ hypothetical_cume_dist_final _null_ _null_ _null_ ));
+DESCR("aggregate final function");
+DATA(insert OID = 3992 ( dense_rank			PGNSP PGUID 12 1 0 2276 0 t f f f f f i 1 0 20 "2276" "{2276}" "{v}" _null_ _null_	aggregate_dummy _null_ _null_ _null_ ));
+DESCR("rank of hypothetical row without gaps");
+DATA(insert OID = 3993 ( dense_rank_final	PGNSP PGUID 12 1 0 2276 0 f f f f f f i 2 0 20 "2281 2276" "{2281,2276}" "{i,v}" _null_ _null_	hypothetical_dense_rank_final _null_ _null_ _null_ ));
+DESCR("aggregate final function");
+
+
 /*
  * Symbolic values for provolatile column: these indicate whether the result
  * of a function is dependent *only* on the values of its explicit arguments,
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index f8ceb5da2eb..16817b68e77 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -63,6 +63,7 @@ extern void interpret_function_parameter_list(List *parameters,
 								  ArrayType **parameterModes,
 								  ArrayType **parameterNames,
 								  List **parameterDefaults,
+								  Oid *variadicArgType,
 								  Oid *requiredResultType);
 
 /* commands/operatorcmds.c */
diff --git a/src/include/fmgr.h b/src/include/fmgr.h
index 1f72e1bd48f..2b41746b56b 100644
--- a/src/include/fmgr.h
+++ b/src/include/fmgr.h
@@ -18,8 +18,12 @@
 #ifndef FMGR_H
 #define FMGR_H
 
-/* We don't want to include primnodes.h here, so make a stub reference */
+/* We don't want to include primnodes.h here, so make some stub references */
 typedef struct Node *fmNodePtr;
+typedef struct Aggref *fmAggrefPtr;
+
+/* Likewise, avoid including execnodes.h here */
+typedef struct ExprContext *fmExprContextPtr;
 
 /* Likewise, avoid including stringinfo.h here */
 typedef struct StringInfoData *fmStringInfo;
@@ -640,8 +644,8 @@ extern void **find_rendezvous_variable(const char *varName);
 /*
  * Support for aggregate functions
  *
- * This is actually in executor/nodeAgg.c, but we declare it here since the
- * whole point is for callers of it to not be overly friendly with nodeAgg.
+ * These are actually in executor/nodeAgg.c, but we declare them here since
+ * the whole point is for callers to not be overly friendly with nodeAgg.
  */
 
 /* AggCheckCallContext can return one of the following codes, or 0: */
@@ -650,6 +654,9 @@ extern void **find_rendezvous_variable(const char *varName);
 
 extern int AggCheckCallContext(FunctionCallInfo fcinfo,
 					MemoryContext *aggcontext);
+extern fmAggrefPtr AggGetAggref(FunctionCallInfo fcinfo);
+extern fmExprContextPtr AggGetPerTupleEContext(FunctionCallInfo fcinfo);
+extern fmExprContextPtr AggGetPerAggEContext(FunctionCallInfo fcinfo);
 
 /*
  * We allow plugin modules to hook function entry/exit.  This is intended
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 5a4034729cf..2a7b36e148f 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -141,7 +141,7 @@ typedef struct ExprContext
 	/* Link to containing EState (NULL if a standalone ExprContext) */
 	struct EState *ecxt_estate;
 
-	/* Functions to call back when ExprContext is shut down */
+	/* Functions to call back when ExprContext is shut down or rescanned */
 	ExprContext_CB *ecxt_callbacks;
 } ExprContext;
 
@@ -587,8 +587,9 @@ typedef struct WholeRowVarExprState
 typedef struct AggrefExprState
 {
 	ExprState	xprstate;
-	List	   *args;			/* states of argument expressions */
-	ExprState  *aggfilter;		/* FILTER expression */
+	List	   *aggdirectargs;	/* states of direct-argument expressions */
+	List	   *args;			/* states of aggregated-argument expressions */
+	ExprState  *aggfilter;		/* state of FILTER expression, if any */
 	int			aggno;			/* ID number for agg within its plan node */
 } AggrefExprState;
 
@@ -1704,6 +1705,7 @@ typedef struct AggState
 	AggStatePerAgg peragg;		/* per-Aggref information */
 	MemoryContext aggcontext;	/* memory context for long-lived data */
 	ExprContext *tmpcontext;	/* econtext for input expressions */
+	AggStatePerAgg curperagg;	/* identifies currently active aggregate */
 	bool		agg_done;		/* indicates completion of Agg scan */
 	/* these fields are used in AGG_PLAIN and AGG_SORTED modes: */
 	AggStatePerGroup pergroup;	/* per-Aggref-per-group working state */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 6a5a8c5f2d7..e89d93034fb 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -281,7 +281,8 @@ typedef struct CollateClause
 /*
  * FuncCall - a function or aggregate invocation
  *
- * agg_order (if not NIL) indicates we saw 'foo(... ORDER BY ...)'.
+ * agg_order (if not NIL) indicates we saw 'foo(... ORDER BY ...)', or if
+ * agg_within_group is true, it was 'foo(...) WITHIN GROUP (ORDER BY ...)'.
  * agg_star indicates we saw a 'foo(*)' construct, while agg_distinct
  * indicates we saw 'foo(DISTINCT ...)'.  In any of these cases, the
  * construct *must* be an aggregate call.  Otherwise, it might be either an
@@ -298,6 +299,7 @@ typedef struct FuncCall
 	List	   *args;			/* the arguments (list of exprs) */
 	List	   *agg_order;		/* ORDER BY (list of SortBy) */
 	Node	   *agg_filter;		/* FILTER clause, if any */
+	bool		agg_within_group;		/* ORDER BY appeared in WITHIN GROUP */
 	bool		agg_star;		/* argument was really '*' */
 	bool		agg_distinct;	/* arguments were labeled DISTINCT */
 	bool		func_variadic;	/* last argument was labeled VARIADIC */
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 791853730b3..16144d45764 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -225,8 +225,9 @@ typedef struct Param
 /*
  * Aggref
  *
- * The aggregate's args list is a targetlist, ie, a list of TargetEntry nodes
- * (before Postgres 9.0 it was just bare expressions).	The non-resjunk TLEs
+ * The aggregate's args list is a targetlist, ie, a list of TargetEntry nodes.
+ *
+ * For a normal (non-ordered-set) aggregate, the non-resjunk TargetEntries
  * represent the aggregate's regular arguments (if any) and resjunk TLEs can
  * be added at the end to represent ORDER BY expressions that are not also
  * arguments.  As in a top-level Query, the TLEs can be marked with
@@ -236,6 +237,12 @@ typedef struct Param
  * they are passed to the transition function.	The grammar only allows a
  * simple "DISTINCT" specifier for the arguments, but we use the full
  * query-level representation to allow more code sharing.
+ *
+ * For an ordered-set aggregate, the args list represents the WITHIN GROUP
+ * (aggregated) arguments, all of which will be listed in the aggorder list.
+ * DISTINCT is not supported in this case, so aggdistinct will be NIL.
+ * The direct arguments appear in aggdirectargs (as a list of plain
+ * expressions, not TargetEntry nodes).
  */
 typedef struct Aggref
 {
@@ -244,12 +251,14 @@ typedef struct Aggref
 	Oid			aggtype;		/* type Oid of result of the aggregate */
 	Oid			aggcollid;		/* OID of collation of result */
 	Oid			inputcollid;	/* OID of collation that function should use */
-	List	   *args;			/* arguments and sort expressions */
+	List	   *aggdirectargs;	/* direct arguments, if an ordered-set agg */
+	List	   *args;			/* aggregated arguments and sort expressions */
 	List	   *aggorder;		/* ORDER BY (list of SortGroupClause) */
 	List	   *aggdistinct;	/* DISTINCT (list of SortGroupClause) */
-	Expr	   *aggfilter;		/* FILTER expression */
+	Expr	   *aggfilter;		/* FILTER expression, if any */
 	bool		aggstar;		/* TRUE if argument list was really '*' */
 	bool		aggvariadic;	/* TRUE if VARIADIC was used in call */
+	char		aggkind;		/* aggregate kind (see pg_aggregate.h) */
 	Index		agglevelsup;	/* > 0 if agg belongs to outer query */
 	int			location;		/* token location, or -1 if unknown */
 } Aggref;
@@ -265,7 +274,7 @@ typedef struct WindowFunc
 	Oid			wincollid;		/* OID of collation of result */
 	Oid			inputcollid;	/* OID of collation that function should use */
 	List	   *args;			/* arguments to the window function */
-	Expr	   *aggfilter;		/* FILTER expression */
+	Expr	   *aggfilter;		/* FILTER expression, if any */
 	Index		winref;			/* index of associated WindowClause */
 	bool		winstar;		/* TRUE if argument list was really '*' */
 	bool		winagg;			/* is function a simple aggregate? */
diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h
index 6d7b5948cd9..a9219e0be95 100644
--- a/src/include/nodes/relation.h
+++ b/src/include/nodes/relation.h
@@ -47,15 +47,16 @@ typedef struct QualCost
 
 /*
  * Costing aggregate function execution requires these statistics about
- * the aggregates to be executed by a given Agg node.  Note that transCost
- * includes the execution costs of the aggregates' input expressions.
+ * the aggregates to be executed by a given Agg node.  Note that the costs
+ * include the execution costs of the aggregates' argument expressions as
+ * well as the aggregate functions themselves.
  */
 typedef struct AggClauseCosts
 {
 	int			numAggs;		/* total number of aggregate functions */
-	int			numOrderedAggs; /* number that use DISTINCT or ORDER BY */
+	int			numOrderedAggs; /* number w/ DISTINCT/ORDER BY/WITHIN GROUP */
 	QualCost	transCost;		/* total per-input-row execution costs */
-	Cost		finalCost;		/* total costs of agg final functions */
+	Cost		finalCost;		/* total per-aggregated-row costs */
 	Size		transitionSpace;	/* space for pass-by-ref transition data */
 } AggClauseCosts;
 
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 8bd34d6e8f0..ab2715629c0 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -412,6 +412,7 @@ PG_KEYWORD("where", WHERE, RESERVED_KEYWORD)
 PG_KEYWORD("whitespace", WHITESPACE_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("window", WINDOW, RESERVED_KEYWORD)
 PG_KEYWORD("with", WITH, RESERVED_KEYWORD)
+PG_KEYWORD("within", WITHIN, UNRESERVED_KEYWORD)
 PG_KEYWORD("without", WITHOUT, UNRESERVED_KEYWORD)
 PG_KEYWORD("work", WORK, UNRESERVED_KEYWORD)
 PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD)
diff --git a/src/include/parser/parse_agg.h b/src/include/parser/parse_agg.h
index b6d9dd37b04..487d5cc8894 100644
--- a/src/include/parser/parse_agg.h
+++ b/src/include/parser/parse_agg.h
@@ -23,8 +23,17 @@ extern void transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
 
 extern void parseCheckAggregates(ParseState *pstate, Query *qry);
 
+extern int	get_aggregate_argtypes(Aggref *aggref, Oid *inputTypes);
+
+extern Oid resolve_aggregate_transtype(Oid aggfuncid,
+							Oid aggtranstype,
+							Oid *inputTypes,
+							int numArguments);
+
 extern void build_aggregate_fnexprs(Oid *agg_input_types,
 						int agg_num_inputs,
+						int agg_num_direct_inputs,
+						bool agg_ordered_set,
 						bool agg_variadic,
 						Oid agg_state_type,
 						Oid agg_result_type,
diff --git a/src/include/parser/parse_clause.h b/src/include/parser/parse_clause.h
index 9bdb03347ad..18f338d3404 100644
--- a/src/include/parser/parse_clause.h
+++ b/src/include/parser/parse_clause.h
@@ -42,6 +42,9 @@ extern List *transformDistinctClause(ParseState *pstate,
 extern List *transformDistinctOnClause(ParseState *pstate, List *distinctlist,
 						  List **targetlist, List *sortClause);
 
+extern List *addTargetToSortList(ParseState *pstate, TargetEntry *tle,
+					List *sortlist, List *targetlist, SortBy *sortby,
+					bool resolveUnknown);
 extern Index assignSortGroupRef(TargetEntry *tle, List *tlist);
 extern bool targetIsInSortList(TargetEntry *tle, Oid sortop, List *sortList);
 
diff --git a/src/include/parser/parse_func.h b/src/include/parser/parse_func.h
index d33eef3482c..f28fd9974c3 100644
--- a/src/include/parser/parse_func.h
+++ b/src/include/parser/parse_func.h
@@ -43,9 +43,7 @@ typedef enum
 
 
 extern Node *ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs,
-				  List *agg_order, Expr *agg_filter,
-				  bool agg_star, bool agg_distinct, bool func_variadic,
-				  WindowDef *over, bool is_column, int location);
+				  FuncCall *fn, int location);
 
 extern FuncDetailCode func_get_detail(List *funcname,
 				List *fargs, List *fargnames,
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 1bfd145da50..4ad900ed2cf 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -515,6 +515,21 @@ extern Datum oidvectorgt(PG_FUNCTION_ARGS);
 extern oidvector *buildoidvector(const Oid *oids, int n);
 extern Oid	oidparse(Node *node);
 
+/* orderedsetaggs.c */
+extern Datum ordered_set_transition(PG_FUNCTION_ARGS);
+extern Datum ordered_set_transition_multi(PG_FUNCTION_ARGS);
+extern Datum percentile_disc_final(PG_FUNCTION_ARGS);
+extern Datum percentile_cont_float8_final(PG_FUNCTION_ARGS);
+extern Datum percentile_cont_interval_final(PG_FUNCTION_ARGS);
+extern Datum percentile_disc_multi_final(PG_FUNCTION_ARGS);
+extern Datum percentile_cont_float8_multi_final(PG_FUNCTION_ARGS);
+extern Datum percentile_cont_interval_multi_final(PG_FUNCTION_ARGS);
+extern Datum mode_final(PG_FUNCTION_ARGS);
+extern Datum hypothetical_rank_final(PG_FUNCTION_ARGS);
+extern Datum hypothetical_percent_rank_final(PG_FUNCTION_ARGS);
+extern Datum hypothetical_cume_dist_final(PG_FUNCTION_ARGS);
+extern Datum hypothetical_dense_rank_final(PG_FUNCTION_ARGS);
+
 /* pseudotypes.c */
 extern Datum cstring_in(PG_FUNCTION_ARGS);
 extern Datum cstring_out(PG_FUNCTION_ARGS);
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index 49f459ad580..dfba74c47d3 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -90,6 +90,7 @@ extern Oid	get_func_namespace(Oid funcid);
 extern Oid	get_func_rettype(Oid funcid);
 extern int	get_func_nargs(Oid funcid);
 extern Oid	get_func_signature(Oid funcid, Oid **argtypes, int *nargs);
+extern Oid	get_func_variadictype(Oid funcid);
 extern bool get_func_retset(Oid funcid);
 extern bool func_strict(Oid funcid);
 extern char func_volatile(Oid funcid);
diff --git a/src/include/utils/tuplesort.h b/src/include/utils/tuplesort.h
index 25fa6de18e1..5f87254881e 100644
--- a/src/include/utils/tuplesort.h
+++ b/src/include/utils/tuplesort.h
@@ -99,6 +99,9 @@ extern IndexTuple tuplesort_getindextuple(Tuplesortstate *state, bool forward,
 extern bool tuplesort_getdatum(Tuplesortstate *state, bool forward,
 				   Datum *val, bool *isNull);
 
+extern bool tuplesort_skiptuples(Tuplesortstate *state, int64 ntuples,
+					 bool forward);
+
 extern void tuplesort_end(Tuplesortstate *state);
 
 extern void tuplesort_get_stats(Tuplesortstate *state,