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--
-- num_nulls()
--
SELECT num_nonnulls(NULL);
num_nonnulls
--------------
0
(1 row)
SELECT num_nonnulls('1');
num_nonnulls
--------------
1
(1 row)
SELECT num_nonnulls(NULL::text);
num_nonnulls
--------------
0
(1 row)
SELECT num_nonnulls(NULL::text, NULL::int);
num_nonnulls
--------------
0
(1 row)
SELECT num_nonnulls(1, 2, NULL::text, NULL::point, '', int8 '9', 1.0 / NULL);
num_nonnulls
--------------
4
(1 row)
SELECT num_nonnulls(VARIADIC '{1,2,NULL,3}'::int[]);
num_nonnulls
--------------
3
(1 row)
SELECT num_nonnulls(VARIADIC '{"1","2","3","4"}'::text[]);
num_nonnulls
--------------
4
(1 row)
SELECT num_nonnulls(VARIADIC ARRAY(SELECT CASE WHEN i <> 40 THEN i END FROM generate_series(1, 100) i));
num_nonnulls
--------------
99
(1 row)
SELECT num_nulls(NULL);
num_nulls
-----------
1
(1 row)
SELECT num_nulls('1');
num_nulls
-----------
0
(1 row)
SELECT num_nulls(NULL::text);
num_nulls
-----------
1
(1 row)
SELECT num_nulls(NULL::text, NULL::int);
num_nulls
-----------
2
(1 row)
SELECT num_nulls(1, 2, NULL::text, NULL::point, '', int8 '9', 1.0 / NULL);
num_nulls
-----------
3
(1 row)
SELECT num_nulls(VARIADIC '{1,2,NULL,3}'::int[]);
num_nulls
-----------
1
(1 row)
SELECT num_nulls(VARIADIC '{"1","2","3","4"}'::text[]);
num_nulls
-----------
0
(1 row)
SELECT num_nulls(VARIADIC ARRAY(SELECT CASE WHEN i <> 40 THEN i END FROM generate_series(1, 100) i));
num_nulls
-----------
1
(1 row)
-- special cases
SELECT num_nonnulls(VARIADIC NULL::text[]);
num_nonnulls
--------------
(1 row)
SELECT num_nonnulls(VARIADIC '{}'::int[]);
num_nonnulls
--------------
0
(1 row)
SELECT num_nulls(VARIADIC NULL::text[]);
num_nulls
-----------
(1 row)
SELECT num_nulls(VARIADIC '{}'::int[]);
num_nulls
-----------
0
(1 row)
-- should fail, one or more arguments is required
SELECT num_nonnulls();
ERROR: function num_nonnulls() does not exist
LINE 1: SELECT num_nonnulls();
^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
SELECT num_nulls();
ERROR: function num_nulls() does not exist
LINE 1: SELECT num_nulls();
^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
--
-- 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);
QUERY PLAN
----------------------------------------------
Hash Join
Hash Cond: (b.unique1 = a.unique1)
-> Seq Scan on tenk1 b
-> Hash
-> Seq Scan on tenk1 a
Filter: my_int_eq(unique2, 42)
(6 rows)
-- 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);
QUERY PLAN
-------------------------------------------------
Nested Loop
-> Seq Scan on tenk1 a
Filter: my_int_eq(unique2, 42)
-> Index Scan using tenk1_unique1 on tenk1 b
Index Cond: (unique1 = a.unique1)
(5 rows)
-- 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;
QUERY PLAN
----------------------------------------
Hash Join
Hash Cond: (g.g = a.unique1)
-> Function Scan on my_gen_series g
-> Hash
-> Seq Scan on tenk1 a
(5 rows)
EXPLAIN (COSTS OFF)
SELECT * FROM tenk1 a JOIN my_gen_series(1,10) g ON a.unique1 = g;
QUERY PLAN
-------------------------------------------------
Nested Loop
-> Function Scan on my_gen_series g
-> Index Scan using tenk1_unique1 on tenk1 a
Index Cond: (unique1 = g.g)
(4 rows)
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