Re: problems doing sub-selects on PostgreSQL 7.1.3 and Solaris 7
От | Heather Johnson |
---|---|
Тема | Re: problems doing sub-selects on PostgreSQL 7.1.3 and Solaris 7 |
Дата | |
Msg-id | 01e401c18252$c9449a10$510b10ac@sephie обсуждение исходный текст |
Ответ на | problems doing sub-selects on PostgreSQL 7.1.3 and Solaris 7 ("Heather Johnson" <hjohnson@nypost.com>) |
Список | pgsql-admin |
Thanks Brandon---that's a very good idea. I'd still like to know why my x86 box can handle the less effecient query better than an E-450, but this is what I'll do until I can get my curiosity satisfied. ;) Heather ----- Original Message ----- From: "bpalmer" <bpalmer@crimelabs.net> To: "Heather Johnson" <hjohnson@nypost.com> Cc: <pgsql-admin@postgresql.org> Sent: Monday, December 10, 2001 5:34 PM Subject: Re: [ADMIN] problems doing sub-selects on PostgreSQL 7.1.3 and Solaris 7 > > SELECT count(*) FROM users WHERE id NOT IN ( SELECT users_id FROM users_demographics ); > > I'm not sure about the difference in speed, but try the following for a > much faster query: > > SELECT count(id) > FROM users > > EXCEPT > > SELECT users_id > FROM users_demographics > > Should be a great deal faster. > > - Brandon > > > > -------------------------------------------------------------------------- -- > c: 646-456-5455 h: 201-798-4983 > b. palmer, bpalmer@crimelabs.net pgp:crimelabs.net/bpalmer.pgp5 >
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