--
-- num_nulls()
--

SELECT num_nonnulls(NULL);
SELECT num_nonnulls('1');
SELECT num_nonnulls(NULL::text);
SELECT num_nonnulls(NULL::text, NULL::int);
SELECT num_nonnulls(1, 2, NULL::text, NULL::point, '', int8 '9', 1.0 / NULL);
SELECT num_nonnulls(VARIADIC '{1,2,NULL,3}'::int[]);
SELECT num_nonnulls(VARIADIC '{"1","2","3","4"}'::text[]);
SELECT num_nonnulls(VARIADIC ARRAY(SELECT CASE WHEN i <> 40 THEN i END FROM generate_series(1, 100) i));

SELECT num_nulls(NULL);
SELECT num_nulls('1');
SELECT num_nulls(NULL::text);
SELECT num_nulls(NULL::text, NULL::int);
SELECT num_nulls(1, 2, NULL::text, NULL::point, '', int8 '9', 1.0 / NULL);
SELECT num_nulls(VARIADIC '{1,2,NULL,3}'::int[]);
SELECT num_nulls(VARIADIC '{"1","2","3","4"}'::text[]);
SELECT num_nulls(VARIADIC ARRAY(SELECT CASE WHEN i <> 40 THEN i END FROM generate_series(1, 100) i));

-- special cases
SELECT num_nonnulls(VARIADIC NULL::text[]);
SELECT num_nonnulls(VARIADIC '{}'::int[]);
SELECT num_nulls(VARIADIC NULL::text[]);
SELECT num_nulls(VARIADIC '{}'::int[]);

-- should fail, one or more arguments is required
SELECT num_nonnulls();
SELECT num_nulls();

--
-- Test adding a support function to a subject function
--

CREATE FUNCTION my_int_eq(int, int) RETURNS bool
  LANGUAGE internal STRICT IMMUTABLE PARALLEL SAFE
  AS $$int4eq$$;

-- By default, planner does not think that's selective
EXPLAIN (COSTS OFF)
SELECT * FROM tenk1 a JOIN tenk1 b ON a.unique1 = b.unique1
WHERE my_int_eq(a.unique2, 42);

-- With support function that knows it's int4eq, we get a different plan
ALTER FUNCTION my_int_eq(int, int) SUPPORT test_support_func;

EXPLAIN (COSTS OFF)
SELECT * FROM tenk1 a JOIN tenk1 b ON a.unique1 = b.unique1
WHERE my_int_eq(a.unique2, 42);

-- Also test non-default rowcount estimate
CREATE FUNCTION my_gen_series(int, int) RETURNS SETOF integer
  LANGUAGE internal STRICT IMMUTABLE PARALLEL SAFE
  AS $$generate_series_int4$$
  SUPPORT test_support_func;

EXPLAIN (COSTS OFF)
SELECT * FROM tenk1 a JOIN my_gen_series(1,1000) g ON a.unique1 = g;

EXPLAIN (COSTS OFF)
SELECT * FROM tenk1 a JOIN my_gen_series(1,10) g ON a.unique1 = g;