BEGIN;
CREATE OR REPLACE FUNCTION assa()
  RETURNS SETOF RECORD AS
$BODY$

	SELECT ROW (1,'assa' )
	UNION ALL SELECT  (2,'assa','assa' )
	UNION ALL SELECT  ROW (3,'assa','assa','assa');
$BODY$
  LANGUAGE sql IMMUTABLE
  COST 10
  ROWS 10;

SELECT assa();
------------------------------------
'(1,assa)'
'(2,assa,assa)'
'(3,assa,assa,assa)'

BEGIN;
CREATE OR REPLACE FUNCTION assa2()
  RETURNS SETOF RECORD AS
$BODY$
BEGIN
	/*
	return NEXT (ROW (1,'assa' ));
	return NEXT (ROW (2,'assa','assa' ));
	return NEXT (ROW (3,'assa','assa','assa'));
	*/
	RETURN QUERY 
		SELECT ROW (1,'assa' )
		UNION ALL SELECT  (2,'assa','assa' )
		UNION ALL SELECT  ROW (3,'assa','assa','assa');
	RETURN;
END
$BODY$
  LANGUAGE plpgsql IMMUTABLE
  COST 10
  ROWS 10;

SELECT assa2();
--------------------------------------
ERROR: set-valued function called in context that cannot accept a set
SQL-состояние: 0A000
Контекст: PL/pgSQL function assa2() line 8 at RETURN QUERY

BEGIN;
CREATE OR REPLACE FUNCTION public.assa()
  RETURNS SETOF RECORD AS
$BODY$

	SELECT ROW (1,'assa' )
	UNION ALL SELECT  (2,'assa','assa' )
	UNION ALL SELECT  ROW (3,'assa','assa','assa');
$BODY$
  LANGUAGE sql IMMUTABLE SECURITY DEFINER
  COST 10
  ROWS 10;
  
	GRANT EXECUTE ON FUNCTION  public.assa() TO public;
	GRANT USAGE  ON schema public TO stats_reader;
	SET ROLE stats_reader;
SELECT public.assa();
-- rollback;
--------------------------
'(1,assa)'
'(2,assa,assa)'
'(3,assa,assa,assa)'