Document get_call_result_type() and friends; mark TypeGetTupleDesc()

and RelationNameGetTupleDesc() as deprecated; remove uses of the
latter in the contrib library.  Along the way, clean up crosstab()
code and documentation a little.

5 files changed, 209 insertions, 139 deletions

diff --git a/contrib/tablefunc/README.tablefunc b/contrib/tablefunc/README.tablefunc
index 7097ef0095..63b1c17d8e 100644
--- a/contrib/tablefunc/README.tablefunc
+++ b/contrib/tablefunc/README.tablefunc
@@ -57,11 +57,16 @@ Installation:
         but you can create additional crosstab functions per the instructions
         in the documentation below.
 
-    crosstab(text sql, N int)
+    crosstab(text sql)
       - returns a set of row_name plus N category value columns
       - requires anonymous composite type syntax in the FROM clause. See
         the instructions in the documentation below.
 
+    crosstab(text sql, N int)
+      - obsolete version of crosstab()
+      - the argument N is now ignored, since the number of value columns
+        is always determined by the calling query
+
     connectby(text relname, text keyid_fld, text parent_keyid_fld
                 [, text orderby_fld], text start_with, int max_depth
 								[, text branch_delim])
@@ -133,7 +138,7 @@ Inputs
 
     A SQL statement which produces the source set of data. The SQL statement
     must return one row_name column, one category column, and one value
-    column.
+    column.  row_name and value must be of type text.
 
     e.g. provided sql must produce a set something like:
 
@@ -152,15 +157,15 @@ Outputs
 
   Returns setof tablefunc_crosstab_N, which is defined by:
 
-    CREATE VIEW tablefunc_crosstab_N AS
-      SELECT
-        ''::TEXT AS row_name,
-        ''::TEXT AS category_1,
-        ''::TEXT AS category_2,
+    CREATE TYPE tablefunc_crosstab_N AS (
+        row_name TEXT,
+        category_1 TEXT,
+        category_2 TEXT,
             .
             .
             .
-        ''::TEXT AS category_N;
+        category_N TEXT
+    );
 
      for the default installed functions, where N is 2, 3, or 4.
 
@@ -188,31 +193,9 @@ Notes
 
   6. The installed defaults are for illustration purposes. You
      can create your own return types and functions based on the
-     crosstab() function of the installed library.
-
-     The return type must have a first column that matches the data
-     type of the sql set used as its source. The subsequent category
-     columns must have the same data type as the value column of the
-     sql result set.
-
-     Create a VIEW to define your return type, similar to the VIEWS
-     in the provided installation script. Then define a unique function
-     name accepting one text parameter and returning setof your_view_name.
-     For example, if your source data produces row_names that are TEXT,
-     and values that are FLOAT8, and you want 5 category columns:
+     crosstab() function of the installed library.  See below for
+     details.
 
-      CREATE VIEW my_crosstab_float8_5_cols AS
-        SELECT
-          ''::TEXT AS row_name,
-          0::FLOAT8 AS category_1,
-          0::FLOAT8 AS category_2,
-          0::FLOAT8 AS category_3,
-          0::FLOAT8 AS category_4,
-          0::FLOAT8 AS category_5;
-
-      CREATE OR REPLACE FUNCTION crosstab_float8_5_cols(text)
-        RETURNS setof my_crosstab_float8_5_cols
-        AS '$libdir/tablefunc','crosstab' LANGUAGE 'c' STABLE STRICT;
 
 Example usage
 
@@ -241,11 +224,12 @@ select * from crosstab3(
 ==================================================================
 Name
 
-crosstab(text, int) - returns a set of row_name
-                      plus N category value columns
+crosstab(text) - returns a set of row_names plus category value columns
 
 Synopsis
 
+crosstab(text sql)
+
 crosstab(text sql, int N)
 
 Inputs
@@ -271,15 +255,16 @@ Inputs
 
   N
 
-    number of category value columns
+    Obsolete argument; ignored if supplied (formerly this had to match
+    the number of category columns determined by the calling query)
 
 Outputs
 
-  Returns setof record, which must defined with a column definition
+  Returns setof record, which must be defined with a column definition
   in the FROM clause of the SELECT statement, e.g.:
 
     SELECT *
-    FROM crosstab(sql, 2) AS ct(row_name text, category_1 text, category_2 text);
+    FROM crosstab(sql) AS ct(row_name text, category_1 text, category_2 text);
 
     the example crosstab function produces a set something like:
                       <== values  columns ==>
@@ -292,9 +277,12 @@ Notes
 
   1. The sql result must be ordered by 1,2.
 
-  2. The number of values columns is determined at run-time. The 
-     column definition provided in the FROM clause must provide for
-     N + 1 columns of the proper data types.
+  2. The number of values columns is determined by the column definition
+     provided in the FROM clause.  The FROM clause must define one
+     row_name column (of the same datatype as the first result column
+     of the sql query) followed by N category columns (of the same
+     datatype as the third result column of the sql query).  You can
+     set up as many category columns as you wish.
 
   3. Missing values (i.e. not enough adjacent rows of same row_name to
      fill the number of result values columns) are filled in with nulls.
@@ -304,6 +292,44 @@ Notes
 
   5. Rows with all nulls in the values columns are skipped.
 
+  6. You can avoid always having to write out a FROM clause that defines the
+     output columns by setting up a custom crosstab function that has
+     the desired output row type wired into its definition.
+
+     There are two ways you can set up a custom crosstab function:
+
+     A. Create a composite type to define your return type, similar to the
+     examples in the installation script. Then define a unique function
+     name accepting one text parameter and returning setof your_type_name.
+     For example, if your source data produces row_names that are TEXT,
+     and values that are FLOAT8, and you want 5 category columns:
+
+      CREATE TYPE my_crosstab_float8_5_cols AS (
+          row_name TEXT,
+          category_1 FLOAT8,
+          category_2 FLOAT8,
+          category_3 FLOAT8,
+          category_4 FLOAT8,
+          category_5 FLOAT8
+      );
+
+      CREATE OR REPLACE FUNCTION crosstab_float8_5_cols(text)
+        RETURNS setof my_crosstab_float8_5_cols
+        AS '$libdir/tablefunc','crosstab' LANGUAGE 'c' STABLE STRICT;
+
+      B. Use OUT parameters to define the return type implicitly.
+      The same example could also be done this way:
+
+      CREATE OR REPLACE FUNCTION crosstab_float8_5_cols(IN text,
+          OUT row_name TEXT,
+          OUT category_1 FLOAT8,
+          OUT category_2 FLOAT8,
+          OUT category_3 FLOAT8,
+          OUT category_4 FLOAT8,
+          OUT category_5 FLOAT8)
+        RETURNS setof record
+        AS '$libdir/tablefunc','crosstab' LANGUAGE 'c' STABLE STRICT;
+
 
 Example usage
 
@@ -418,6 +444,10 @@ Notes
 
   5. Rows with a null row_name column are skipped.
 
+  6. You can create predefined functions to avoid having to write out
+     the result column names/types in each query.  See the examples
+     for crosstab(text).
+
 
 Example usage
 
diff --git a/contrib/tablefunc/expected/tablefunc.out b/contrib/tablefunc/expected/tablefunc.out
index d8f4c30a5d..50faf4390f 100644
--- a/contrib/tablefunc/expected/tablefunc.out
+++ b/contrib/tablefunc/expected/tablefunc.out
@@ -102,27 +102,40 @@ SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = '
  test4    | val4       | val5       | val6       | 
 (2 rows)
 
-SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;', 2) AS c(rowid text, att1 text, att2 text);
+SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text);
  rowid | att1 | att2 
 -------+------+------
  test1 | val1 | val2
  test2 | val5 | val6
 (2 rows)
 
-SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;', 3) AS c(rowid text, att1 text, att2 text, att3 text);
+SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text, att3 text);
  rowid | att1 | att2 | att3 
 -------+------+------+------
  test1 | val1 | val2 | val3
  test2 | val5 | val6 | val7
 (2 rows)
 
-SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;', 4) AS c(rowid text, att1 text, att2 text, att3 text, att4 text);
+SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text, att3 text, att4 text);
  rowid | att1 | att2 | att3 | att4 
 -------+------+------+------+------
  test1 | val1 | val2 | val3 | val4
  test2 | val5 | val6 | val7 | val8
 (2 rows)
 
+-- check it works with OUT parameters, too
+CREATE FUNCTION crosstab_out(text,
+	OUT rowid text, OUT att1 text, OUT att2 text, OUT att3 text)
+RETURNS setof record
+AS '$libdir/tablefunc','crosstab'
+LANGUAGE 'C' STABLE STRICT;
+SELECT * FROM crosstab_out('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
+ rowid | att1 | att2 | att3 
+-------+------+------+------
+ test1 | val1 | val2 | val3
+ test2 | val5 | val6 | val7
+(2 rows)
+
 --
 -- hash based crosstab
 --
@@ -211,6 +224,40 @@ AS c(rowid text, rowdt timestamp, temperature text, test_result text, test_start
 -------+-------+-------------+-------------+----------------+-------
 (0 rows)
 
+-- check it works with a named result rowtype
+create type my_crosstab_result as (
+  rowid text, rowdt timestamp,
+  temperature int4, test_result text, test_startdate timestamp, volts float8);
+CREATE FUNCTION crosstab_named(text, text)
+RETURNS setof my_crosstab_result
+AS '$libdir/tablefunc','crosstab_hash'
+LANGUAGE 'C' STABLE STRICT;
+SELECT * FROM crosstab_named(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1');
+ rowid |          rowdt           | temperature | test_result |      test_startdate      | volts  
+-------+--------------------------+-------------+-------------+--------------------------+--------
+ test1 | Sat Mar 01 00:00:00 2003 |          42 | PASS        |                          | 2.6987
+ test2 | Sun Mar 02 00:00:00 2003 |          53 | FAIL        | Sat Mar 01 00:00:00 2003 | 3.1234
+(2 rows)
+
+-- check it works with OUT parameters
+CREATE FUNCTION crosstab_out(text, text,
+  OUT rowid text, OUT rowdt timestamp,
+  OUT temperature int4, OUT test_result text,
+  OUT test_startdate timestamp, OUT volts float8)
+RETURNS setof record
+AS '$libdir/tablefunc','crosstab_hash'
+LANGUAGE 'C' STABLE STRICT;
+SELECT * FROM crosstab_out(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1');
+ rowid |          rowdt           | temperature | test_result |      test_startdate      | volts  
+-------+--------------------------+-------------+-------------+--------------------------+--------
+ test1 | Sat Mar 01 00:00:00 2003 |          42 | PASS        |                          | 2.6987
+ test2 | Sun Mar 02 00:00:00 2003 |          53 | FAIL        | Sat Mar 01 00:00:00 2003 | 3.1234
+(2 rows)
+
 --
 -- connectby
 --
diff --git a/contrib/tablefunc/sql/tablefunc.sql b/contrib/tablefunc/sql/tablefunc.sql
index c464acbd3b..3229086133 100644
--- a/contrib/tablefunc/sql/tablefunc.sql
+++ b/contrib/tablefunc/sql/tablefunc.sql
@@ -34,9 +34,19 @@ SELECT * FROM crosstab2('SELECT rowid, attribute, val FROM ct where rowclass = '
 SELECT * FROM crosstab3('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' ORDER BY 1,2;');
 SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' ORDER BY 1,2;');
 
-SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;', 2) AS c(rowid text, att1 text, att2 text);
-SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;', 3) AS c(rowid text, att1 text, att2 text, att3 text);
-SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;', 4) AS c(rowid text, att1 text, att2 text, att3 text, att4 text);
+SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text);
+SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text, att3 text);
+SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text, att3 text, att4 text);
+
+-- check it works with OUT parameters, too
+
+CREATE FUNCTION crosstab_out(text,
+	OUT rowid text, OUT att1 text, OUT att2 text, OUT att3 text)
+RETURNS setof record
+AS '$libdir/tablefunc','crosstab'
+LANGUAGE 'C' STABLE STRICT;
+
+SELECT * FROM crosstab_out('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
 
 --
 -- hash based crosstab
@@ -100,6 +110,35 @@ SELECT * FROM crosstab(
   'SELECT DISTINCT attribute FROM cth WHERE false ORDER BY 1')
 AS c(rowid text, rowdt timestamp, temperature text, test_result text, test_startdate text, volts text);
 
+-- check it works with a named result rowtype
+
+create type my_crosstab_result as (
+  rowid text, rowdt timestamp,
+  temperature int4, test_result text, test_startdate timestamp, volts float8);
+
+CREATE FUNCTION crosstab_named(text, text)
+RETURNS setof my_crosstab_result
+AS '$libdir/tablefunc','crosstab_hash'
+LANGUAGE 'C' STABLE STRICT;
+
+SELECT * FROM crosstab_named(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1');
+
+-- check it works with OUT parameters
+
+CREATE FUNCTION crosstab_out(text, text,
+  OUT rowid text, OUT rowdt timestamp,
+  OUT temperature int4, OUT test_result text,
+  OUT test_startdate timestamp, OUT volts float8)
+RETURNS setof record
+AS '$libdir/tablefunc','crosstab_hash'
+LANGUAGE 'C' STABLE STRICT;
+
+SELECT * FROM crosstab_out(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1');
+
 --
 -- connectby
 --
diff --git a/contrib/tablefunc/tablefunc.c b/contrib/tablefunc/tablefunc.c
index 0aa52b5281..6ab79ebeff 100644
--- a/contrib/tablefunc/tablefunc.c
+++ b/contrib/tablefunc/tablefunc.c
@@ -51,8 +51,6 @@ static void validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch, bool
 static bool compatCrosstabTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
 static bool compatConnectbyTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
 static void get_normal_pair(float8 *x1, float8 *x2);
-static TupleDesc make_crosstab_tupledesc(TupleDesc spi_tupdesc,
-						int num_categories);
 static Tuplestorestate *connectby(char *relname,
 		  char *key_fld,
 		  char *parent_key_fld,
@@ -332,12 +330,14 @@ get_normal_pair(float8 *x1, float8 *x2)
  * NOTES:
  * 1. SQL result must be ordered by 1,2.
  * 2. The number of values columns depends on the tuple description
- *	  of the function's declared return type.
- * 2. Missing values (i.e. not enough adjacent rows of same rowid to
+ *	  of the function's declared return type.  The return type's columns
+ *    must match the datatypes of the SQL query's result.  The datatype
+ *    of the category column can be anything, however.
+ * 3. Missing values (i.e. not enough adjacent rows of same rowid to
  *	  fill the number of result values columns) are filled in with nulls.
- * 3. Extra values (i.e. too many adjacent rows of same rowid to fill
+ * 4. Extra values (i.e. too many adjacent rows of same rowid to fill
  *	  the number of result values columns) are skipped.
- * 4. Rows with all nulls in the values columns are skipped.
+ * 5. Rows with all nulls in the values columns are skipped.
  */
 PG_FUNCTION_INFO_V1(crosstab);
 Datum
@@ -360,10 +360,7 @@ crosstab(PG_FUNCTION_ARGS)
 	if (SRF_IS_FIRSTCALL())
 	{
 		char	   *sql = GET_STR(PG_GETARG_TEXT_P(0));
-		Oid			funcid = fcinfo->flinfo->fn_oid;
-		Oid			functypeid;
-		char		functyptype;
-		TupleDesc	tupdesc = NULL;
+		TupleDesc	tupdesc;
 		int			ret;
 		int			proc;
 
@@ -391,20 +388,23 @@ crosstab(PG_FUNCTION_ARGS)
 			spi_tuptable = SPI_tuptable;
 			spi_tupdesc = spi_tuptable->tupdesc;
 
-			/*
+			/*----------
 			 * The provided SQL query must always return three columns.
 			 *
-			 * 1. rowname	the label or identifier for each row in the final
-			 * result 2. category  the label or identifier for each column
-			 * in the final result 3. values	the value for each column
-			 * in the final result
+			 * 1. rowname
+			 *	the label or identifier for each row in the final result
+			 * 2. category
+			 *  the label or identifier for each column in the final result
+			 * 3. values
+			 *	the value for each column in the final result
+			 *----------
 			 */
 			if (spi_tupdesc->natts != 3)
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 						 errmsg("invalid source data SQL statement"),
-						 errdetail("The provided SQL must return 3 " \
-							 " columns; rowid, category, and values.")));
+						 errdetail("The provided SQL must return 3 "
+							 "columns: rowid, category, and values.")));
 		}
 		else
 		{
@@ -416,39 +416,31 @@ crosstab(PG_FUNCTION_ARGS)
 		/* SPI switches context on us, so reset it */
 		MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
 
-		/* get the typeid that represents our return type */
-		functypeid = get_func_rettype(funcid);
-
-		/* check typtype to see if we have a predetermined return type */
-		functyptype = get_typtype(functypeid);
-
-		if (functyptype == 'c')
+		/* get a tuple descriptor for our result type */
+		switch (get_call_result_type(fcinfo, NULL, &tupdesc))
 		{
-			/* Build a tuple description for a named composite type */
-			tupdesc = TypeGetTupleDesc(functypeid, NIL);
-		}
-		else if (functypeid == RECORDOID)
-		{
-			if (fcinfo->nargs != 2)
+			case TYPEFUNC_COMPOSITE:
+				/* success */
+				break;
+			case TYPEFUNC_RECORD:
+				/* failed to determine actual type of RECORD */
 				ereport(ERROR,
-						(errcode(ERRCODE_SYNTAX_ERROR),
-						 errmsg("wrong number of arguments")));
-			else
-			{
-				int			num_categories = PG_GETARG_INT32(1);
-
-				tupdesc = make_crosstab_tupledesc(spi_tupdesc, num_categories);
-			}
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("function returning record called in context "
+								"that cannot accept type record")));
+				break;
+			default:
+				/* result type isn't composite */
+				elog(ERROR, "return type must be a row type");
+				break;
 		}
-		else
-			ereport(ERROR,
-					(errcode(ERRCODE_SYNTAX_ERROR),
-					 errmsg("return type must be a row type")));
+
+		/* make sure we have a persistent copy of the tupdesc */
+		tupdesc = CreateTupleDescCopy(tupdesc);
 
 		/*
-		 * Check that return tupdesc is compatible with the one we got
-		 * from ret_relname, at least based on number and type of
-		 * attributes
+		 * Check that return tupdesc is compatible with the data we got
+		 * from SPI, at least based on number and type of attributes
 		 */
 		if (!compatCrosstabTupleDescs(tupdesc, spi_tupdesc))
 			ereport(ERROR,
@@ -679,8 +671,8 @@ crosstab(PG_FUNCTION_ARGS)
  * 1. SQL result must be ordered by 1.
  * 2. The number of values columns depends on the tuple description
  *	  of the function's declared return type.
- * 2. Missing values (i.e. missing category) are filled in with nulls.
- * 3. Extra values (i.e. not in category results) are skipped.
+ * 3. Missing values (i.e. missing category) are filled in with nulls.
+ * 4. Extra values (i.e. not in category results) are skipped.
  */
 PG_FUNCTION_INFO_V1(crosstab_hash);
 Datum
@@ -1628,52 +1620,6 @@ compatCrosstabTupleDescs(TupleDesc ret_tupdesc, TupleDesc sql_tupdesc)
 	return true;
 }
 
-static TupleDesc
-make_crosstab_tupledesc(TupleDesc spi_tupdesc, int num_categories)
-{
-	Form_pg_attribute sql_attr;
-	Oid			sql_atttypid;
-	TupleDesc	tupdesc;
-	int			natts;
-	AttrNumber	attnum;
-	char		attname[NAMEDATALEN];
-	int			i;
-
-	/*
-	 * We need to build a tuple description with one column for the
-	 * rowname, and num_categories columns for the values. Each must be of
-	 * the same type as the corresponding spi result input column.
-	 */
-	natts = num_categories + 1;
-	tupdesc = CreateTemplateTupleDesc(natts, false);
-
-	/* first the rowname column */
-	attnum = 1;
-
-	sql_attr = spi_tupdesc->attrs[0];
-	sql_atttypid = sql_attr->atttypid;
-
-	strcpy(attname, "rowname");
-
-	TupleDescInitEntry(tupdesc, attnum, attname, sql_atttypid,
-					   -1, 0);
-
-	/* now the category values columns */
-	sql_attr = spi_tupdesc->attrs[2];
-	sql_atttypid = sql_attr->atttypid;
-
-	for (i = 0; i < num_categories; i++)
-	{
-		attnum++;
-
-		sprintf(attname, "category_%d", i + 1);
-		TupleDescInitEntry(tupdesc, attnum, attname, sql_atttypid,
-						   -1, 0);
-	}
-
-	return tupdesc;
-}
-
 /*
  * Return a properly quoted literal value.
  * Uses quote_literal in quote.c
diff --git a/contrib/tablefunc/tablefunc.sql.in b/contrib/tablefunc/tablefunc.sql.in
index f3d5d3d8a1..fee9cb7e17 100644
--- a/contrib/tablefunc/tablefunc.sql.in
+++ b/contrib/tablefunc/tablefunc.sql.in
@@ -6,6 +6,13 @@ RETURNS setof float8
 AS 'MODULE_PATHNAME','normal_rand'
 LANGUAGE 'C' VOLATILE STRICT;
 
+-- the generic crosstab function:
+CREATE OR REPLACE FUNCTION crosstab(text)
+RETURNS setof record
+AS 'MODULE_PATHNAME','crosstab'
+LANGUAGE 'C' STABLE STRICT;
+
+-- examples of building custom type-specific crosstab functions:
 CREATE TYPE tablefunc_crosstab_2 AS
 (
 	row_name TEXT,
@@ -45,6 +52,7 @@ RETURNS setof tablefunc_crosstab_4
 AS 'MODULE_PATHNAME','crosstab'
 LANGUAGE 'C' STABLE STRICT;
 
+-- obsolete:
 CREATE OR REPLACE FUNCTION crosstab(text,int)
 RETURNS setof record
 AS 'MODULE_PATHNAME','crosstab'