Re: delete where not in another table

> Subject: [SQL] delete where not in another table
> DELETE FROM T1 WHERE T1.user_id NOT IN (SELECT user_id FROM T2 WHERE T2.user_id=T1.user_id);


Following query use an anti join and is much faster:
 delete from t1 where not exists (select user_id  from t2 where t2.user_id =t1.user_id )

regards,

Marc Mamin