mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-09-13 17:39:36 +02:00
36 lines
858 B
Plaintext
36 lines
858 B
Plaintext
--
|
|
-- RANDOM
|
|
-- Test the random function
|
|
--
|
|
-- count the number of tuples originally
|
|
SELECT count(*) FROM onek;
|
|
count
|
|
-------
|
|
1000
|
|
(1 row)
|
|
|
|
-- select roughly 1/10 of the tuples
|
|
-- Assume that the "onek" table has 1000 tuples
|
|
-- and try to bracket the correct number so we
|
|
-- have a regression test which can pass/fail
|
|
-- - thomas 1998-08-17
|
|
SELECT count(*) AS random INTO RANDOM_TBL
|
|
FROM onek WHERE oidrand(onek.oid, 10);
|
|
-- select again, the count should be different
|
|
INSERT INTO RANDOM_TBL (random)
|
|
SELECT count(*)
|
|
FROM onek WHERE oidrand(onek.oid, 10);
|
|
-- now test the results for randomness in the correct range
|
|
SELECT random, count(random) FROM RANDOM_TBL
|
|
GROUP BY random HAVING count(random) > 1;
|
|
random | count
|
|
--------+-------
|
|
(0 rows)
|
|
|
|
SELECT random FROM RANDOM_TBL
|
|
WHERE random NOT BETWEEN 80 AND 120;
|
|
random
|
|
--------
|
|
(0 rows)
|
|
|