Re: [GENERAL] eliminating records not in (select id ... so SLOW?

Ivan Sergio Borgonovo wrote:

> But what if I *really* had to execute that query?
> Any other magic I could play to speed it up?

A trick that is sometimes spectacularly efficient is to rewrite the
query to use an outer join instead of NOT IN.

Try:

DELETE FROM table1 WHERE id IN
(SELECT table1.id FROM table1 LEFT JOIN table2 ON table1.id=table2.id
WHERE table2.id IS NULL)

Best regards,
--
Daniel
PostgreSQL-powered mail user agent and storage:
http://www.manitou-mail.org

--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general