the best way to get some records not in another table

Hi, all

Try to get some records not in another table. As the following, please
advise which one will be the best way to do. Or is there any other way to do
better?

SELECT DISTINCT a.c1
FROM test_j2 a
WHERE a.c1 NOT IN (SELECT DISTINCT b.c1 FROM test_j1 b);

SELECT a.c1 FROM test_j2 a
EXCEPT
SELECT b.c1 FROM test_j1 b;


Jack