postgresql/src/test/regress/sql/misc_functions.sql

--
-- 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();

--
-- pg_log_backend_memory_contexts()
--
-- Memory contexts are logged and they are not returned to the function.
-- Furthermore, their contents can vary depending on the timing. However,
-- we can at least verify that the code doesn't fail.
--
SELECT * FROM pg_log_backend_memory_contexts(pg_backend_pid());

--
-- Test some built-in SRFs
--
-- The outputs of these are variable, so we can't just print their results
-- directly, but we can at least verify that the code doesn't fail.
--
select setting as segsize
from pg_settings where name = 'wal_segment_size'
\gset

select count(*) > 0 as ok from pg_ls_waldir();
-- Test ProjectSet as well as FunctionScan
select count(*) > 0 as ok from (select pg_ls_waldir()) ss;
-- Test not-run-to-completion cases.
select * from pg_ls_waldir() limit 0;
select count(*) > 0 as ok from (select * from pg_ls_waldir() limit 1) ss;
select (w).size = :segsize as ok
from (select pg_ls_waldir() w) ss where length((w).name) = 24 limit 1;

select count(*) >= 0 as ok from pg_ls_archive_statusdir();

select * from (select pg_ls_dir('.') a) a where a = 'base' limit 1;

select * from (select (pg_timezone_names()).name) ptn where name='UTC' limit 1;

select count(*) > 0 from
  (select pg_tablespace_databases(oid) as pts from pg_tablespace
   where spcname = 'pg_default') pts
  join pg_database db on pts.pts = db.oid;

--
-- 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;