Find duplicate in a database


SELECT my_key, count(*) FROM my_table GROUP BY my_key HAVING count(*) > 1;


Insert timestamps with a loop

This sql command allow you to test data writting in your database. It can be useful to benchmark your disk performances or check the impact of a lock.


INSERT INTO table SELECT timeofday()::timestamp FROM generate_series(1,1000000) WHERE pg_sleep(1) IS NOT NULL;