Implement max() and min() aggregates for array types. Patch from Koju

Iijima, reviewed by Neil Conway. Catalog version number bumped,
regression tests updated.

doc/src/sgml/func.sgml

 <!--
-$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.238 2005/02/11 04:31:54 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.239 2005/02/28 03:45:20 neilc Exp $
 PostgreSQL documentation
 -->
 
@@ -7161,7 +7161,7 @@ SELECT NULLIF(value, '(none)') ...
 
      <row>
       <entry><function>max(<replaceable class="parameter">expression</replaceable>)</function></entry>
-      <entry>any numeric, string, or date/time type</entry>
+      <entry>any array, numeric, string, or date/time type</entry>
       <entry>same as argument type</entry>
       <entry>
        maximum value of <replaceable
@@ -7172,7 +7172,7 @@ SELECT NULLIF(value, '(none)') ...
 
      <row>
       <entry><function>min(<replaceable class="parameter">expression</replaceable>)</function></entry>
-      <entry>any numeric, string, or date/time type</entry>
+      <entry>any array, numeric, string, or date/time type</entry>
       <entry>same as argument type</entry>
       <entry>
        minimum value of <replaceable

src/backend/utils/adt/arrayfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.115 2004/12/31 22:01:21 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.116 2005/02/28 03:45:21 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -3387,3 +3387,33 @@ makeMdArrayResult(ArrayBuildState *astate,
 
 	return PointerGetDatum(result);
 }
+
+Datum
+array_larger(PG_FUNCTION_ARGS)
+{
+	ArrayType	*v1,
+				*v2,
+				*result;
+
+	v1 = PG_GETARG_ARRAYTYPE_P(0);
+	v2 = PG_GETARG_ARRAYTYPE_P(1);
+
+	result = ((array_cmp(fcinfo) > 0) ? v1 : v2);
+
+	PG_RETURN_ARRAYTYPE_P(result);
+}
+
+Datum
+array_smaller(PG_FUNCTION_ARGS)
+{
+	ArrayType	*v1,
+				*v2,
+				*result;
+
+	v1 = PG_GETARG_ARRAYTYPE_P(0);
+	v2 = PG_GETARG_ARRAYTYPE_P(1);
+
+	result = ((array_cmp(fcinfo) < 0) ? v1 : v2);
+
+	PG_RETURN_ARRAYTYPE_P(result);
+}

src/include/catalog/catversion.h

@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.256 2005/02/27 08:31:30 neilc Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.257 2005/02/28 03:45:21 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200502271
+#define CATALOG_VERSION_NO	200502281
 
 #endif

src/include/catalog/pg_aggregate.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_aggregate.h,v 1.48 2005/01/28 17:35:53 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_aggregate.h,v 1.49 2005/02/28 03:45:22 neilc Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -110,6 +110,7 @@ DATA(insert ( 2127	timestamptz_larger	-			1184	_null_ ));
 DATA(insert ( 2128	interval_larger -				1186	_null_ ));
 DATA(insert ( 2129	text_larger		-				25		_null_ ));
 DATA(insert ( 2130	numeric_larger	-				1700	_null_ ));
+DATA(insert ( 2050	array_larger	-				2277    _null_ ));
 
 /* min */
 DATA(insert ( 2131	int8smaller		-				20		_null_ ));
@@ -128,6 +129,7 @@ DATA(insert ( 2143	timestamptz_smaller -			1184	_null_ ));
 DATA(insert ( 2144	interval_smaller	-			1186	_null_ ));
 DATA(insert ( 2145	text_smaller	-				25		_null_ ));
 DATA(insert ( 2146	numeric_smaller -				1700	_null_ ));
+DATA(insert ( 2051	array_smaller	-				2277    _null_ ));
 
 /*
  * Using int8inc for count() is cheating a little, since it really only

src/include/catalog/pg_proc.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.351 2005/02/27 08:31:30 neilc Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.352 2005/02/28 03:45:22 neilc Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -1028,6 +1028,10 @@ DATA(insert OID = 394 (  string_to_array   PGNSP PGUID 12 f f t f i 2 1009 "25 2
 DESCR("split delimited text into text[]");
 DATA(insert OID = 395 (  array_to_string   PGNSP PGUID 12 f f t f i 2 25 "2277 25" _null_ array_to_text - _null_ ));
 DESCR("concatenate array elements, using delimiter, into text");
+DATA(insert OID = 515 (  array_larger	   PGNSP PGUID 12 f f t f i 2 2277 "2277 2277" _null_ array_larger - _null_ ));
+DESCR("larger of two");
+DATA(insert OID = 516 (  array_smaller	   PGNSP PGUID 12 f f t f i 2 2277 "2277 2277" _null_ array_smaller - _null_ ));
+DESCR("smaller of two");
 
 DATA(insert OID = 760 (  smgrin			   PGNSP PGUID 12 f f t f s 1 210 "2275" _null_  smgrin - _null_ ));
 DESCR("I/O");
@@ -3029,6 +3033,7 @@ DATA(insert OID = 2127 (  max				PGNSP PGUID 12 t f f f i 1 1184 "1184" _null_	a
 DATA(insert OID = 2128 (  max				PGNSP PGUID 12 t f f f i 1 1186 "1186" _null_	aggregate_dummy - _null_ ));
 DATA(insert OID = 2129 (  max				PGNSP PGUID 12 t f f f i 1 25 "25" _null_	aggregate_dummy - _null_ ));
 DATA(insert OID = 2130 (  max				PGNSP PGUID 12 t f f f i 1 1700 "1700" _null_	aggregate_dummy - _null_ ));
+DATA(insert OID = 2050 (  max				PGNSP PGUID 12 t f f f i 1 2277 "2277" _null_	aggregate_dummy - _null_ ));
 
 DATA(insert OID = 2131 (  min				PGNSP PGUID 12 t f f f i 1 20 "20" _null_	aggregate_dummy - _null_ ));
 DATA(insert OID = 2132 (  min				PGNSP PGUID 12 t f f f i 1 23 "23" _null_	aggregate_dummy - _null_ ));
@@ -3046,6 +3051,7 @@ DATA(insert OID = 2143 (  min				PGNSP PGUID 12 t f f f i 1 1184 "1184" _null_	a
 DATA(insert OID = 2144 (  min				PGNSP PGUID 12 t f f f i 1 1186 "1186" _null_	aggregate_dummy - _null_ ));
 DATA(insert OID = 2145 (  min				PGNSP PGUID 12 t f f f i 1 25 "25" _null_	aggregate_dummy - _null_ ));
 DATA(insert OID = 2146 (  min				PGNSP PGUID 12 t f f f i 1 1700 "1700" _null_	aggregate_dummy - _null_ ));
+DATA(insert OID = 2051 (  min				PGNSP PGUID 12 t f f f i 1 2277 "2277" _null_	aggregate_dummy - _null_ ));
 
 DATA(insert OID = 2147 (  count				PGNSP PGUID 12 t f f f i 1 20 "2276" _null_  aggregate_dummy - _null_ ));
 

src/include/utils/array.h

@@ -10,7 +10,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/array.h,v 1.51 2004/12/31 22:03:45 pgsql Exp $
+ * $PostgreSQL: pgsql/src/include/utils/array.h,v 1.52 2005/02/28 03:45:23 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -129,6 +129,8 @@ extern Datum array_upper(PG_FUNCTION_ARGS);
 extern Datum array_type_coerce(PG_FUNCTION_ARGS);
 extern Datum array_type_length_coerce(PG_FUNCTION_ARGS);
 extern Datum array_length_coerce(PG_FUNCTION_ARGS);
+extern Datum array_larger(PG_FUNCTION_ARGS);
+extern Datum array_smaller(PG_FUNCTION_ARGS);
 
 extern Datum array_ref(ArrayType *array, int nSubscripts, int *indx,
 		  int arraylen, int elmlen, bool elmbyval, char elmalign,

src/test/regress/expected/arrays.out

@@ -483,3 +483,47 @@ select '{
 (1 row)
 
 -- all of the above should be accepted
+-- tests for array aggregates
+CREATE TEMP TABLE arraggtest ( f1 INT[], f2 TEXT[][], f3 FLOAT[]);
+INSERT INTO arraggtest (f1, f2, f3) VALUES
+('{1,2,3,4}','{{grey,red},{blue,blue}}','{1.6, 0.0}');
+INSERT INTO arraggtest (f1, f2, f3) VALUES
+('{1,2,3}','{{grey,red},{grey,blue}}','{1.6}');
+SELECT max(f1), min(f1), max(f2), min(f2), max(f3), min(f3) FROM arraggtest;
+    max    |   min   |           max            |           min            |   max   |  min  
+-----------+---------+--------------------------+--------------------------+---------+-------
+ {1,2,3,4} | {1,2,3} | {{grey,red},{grey,blue}} | {{grey,red},{blue,blue}} | {1.6,0} | {1.6}
+(1 row)
+
+INSERT INTO arraggtest (f1, f2, f3) VALUES
+('{3,3,2,4,5,6}','{{white,yellow},{pink,orange}}','{2.1,3.3,1.8,1.7,1.6}');
+SELECT max(f1), min(f1), max(f2), min(f2), max(f3), min(f3) FROM arraggtest;
+      max      |   min   |              max               |           min            |          max          |  min  
+---------------+---------+--------------------------------+--------------------------+-----------------------+-------
+ {3,3,2,4,5,6} | {1,2,3} | {{white,yellow},{pink,orange}} | {{grey,red},{blue,blue}} | {2.1,3.3,1.8,1.7,1.6} | {1.6}
+(1 row)
+
+INSERT INTO arraggtest (f1, f2, f3) VALUES
+('{2}','{{black,red},{green,orange}}','{1.6,2.2,2.6,0.4}');
+SELECT max(f1), min(f1), max(f2), min(f2), max(f3), min(f3) FROM arraggtest;
+      max      |   min   |              max               |             min              |          max          |  min  
+---------------+---------+--------------------------------+------------------------------+-----------------------+-------
+ {3,3,2,4,5,6} | {1,2,3} | {{white,yellow},{pink,orange}} | {{black,red},{green,orange}} | {2.1,3.3,1.8,1.7,1.6} | {1.6}
+(1 row)
+
+INSERT INTO arraggtest (f1, f2, f3) VALUES
+('{4,2,6,7,8,1}','{{red},{black},{purple},{blue},{blue}}',NULL);
+SELECT max(f1), min(f1), max(f2), min(f2), max(f3), min(f3) FROM arraggtest;
+      max      |   min   |              max               |             min              |          max          |  min  
+---------------+---------+--------------------------------+------------------------------+-----------------------+-------
+ {4,2,6,7,8,1} | {1,2,3} | {{white,yellow},{pink,orange}} | {{black,red},{green,orange}} | {2.1,3.3,1.8,1.7,1.6} | {1.6}
+(1 row)
+
+INSERT INTO arraggtest (f1, f2, f3) VALUES
+('{}','{{pink,white,blue,red,grey,orange}}','{2.1,1.87,1.4,2.2}');
+SELECT max(f1), min(f1), max(f2), min(f2), max(f3), min(f3) FROM arraggtest;
+      max      | min |              max               |             min              |          max          |  min  
+---------------+-----+--------------------------------+------------------------------+-----------------------+-------
+ {4,2,6,7,8,1} | {}  | {{white,yellow},{pink,orange}} | {{black,red},{green,orange}} | {2.1,3.3,1.8,1.7,1.6} | {1.6}
+(1 row)
+

src/test/regress/sql/arrays.sql

@@ -217,3 +217,28 @@ select '{
            @ 1 hour @ 42 minutes @ 20 seconds
          }'::interval[];
 -- all of the above should be accepted
+
+-- tests for array aggregates
+CREATE TEMP TABLE arraggtest ( f1 INT[], f2 TEXT[][], f3 FLOAT[]);
+
+INSERT INTO arraggtest (f1, f2, f3) VALUES
+('{1,2,3,4}','{{grey,red},{blue,blue}}','{1.6, 0.0}');
+INSERT INTO arraggtest (f1, f2, f3) VALUES
+('{1,2,3}','{{grey,red},{grey,blue}}','{1.6}');
+SELECT max(f1), min(f1), max(f2), min(f2), max(f3), min(f3) FROM arraggtest;
+
+INSERT INTO arraggtest (f1, f2, f3) VALUES
+('{3,3,2,4,5,6}','{{white,yellow},{pink,orange}}','{2.1,3.3,1.8,1.7,1.6}');
+SELECT max(f1), min(f1), max(f2), min(f2), max(f3), min(f3) FROM arraggtest;
+
+INSERT INTO arraggtest (f1, f2, f3) VALUES
+('{2}','{{black,red},{green,orange}}','{1.6,2.2,2.6,0.4}');
+SELECT max(f1), min(f1), max(f2), min(f2), max(f3), min(f3) FROM arraggtest;
+
+INSERT INTO arraggtest (f1, f2, f3) VALUES
+('{4,2,6,7,8,1}','{{red},{black},{purple},{blue},{blue}}',NULL);
+SELECT max(f1), min(f1), max(f2), min(f2), max(f3), min(f3) FROM arraggtest;
+
+INSERT INTO arraggtest (f1, f2, f3) VALUES
+('{}','{{pink,white,blue,red,grey,orange}}','{2.1,1.87,1.4,2.2}');
+SELECT max(f1), min(f1), max(f2), min(f2), max(f3), min(f3) FROM arraggtest;