Received: from localhost (unknown [200.46.204.182]) by postgresql.org (Postfix) with ESMTP id 6C48E2E3006 for ; Wed, 28 Nov 2007 10:15:20 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.182]) (amavisd-maia, port 10024) with ESMTP id 43425-09 for ; Wed, 28 Nov 2007 10:15:09 -0400 (AST) Received: from linus.numail.org (mail.numail.org [216.130.152.7]) by postgresql.org (Postfix) with ESMTP id 7AB8E2E2DEC for ; Wed, 28 Nov 2007 10:15:14 -0400 (AST) Received: (qmail 10802 invoked by uid 0); 28 Nov 2007 14:15:12 -0000 Received: from 72.15.64.64 by linus.numail.org (envelope-from , uid 101) with qmail-scanner-1.23 (fsecure: 4.50/2111/fprot(2004-10-21)/avp(2004-10-21). Clear:RC:1(72.15.64.64):. Processed in 0.083195 secs); 28 Nov 2007 14:15:12 -0000 Received: from unknown (HELO ?24.25.1.100?) (72.15.64.64) by mail.numail.org with AES256-SHA encrypted SMTP; 28 Nov 2007 14:15:12 -0000 Message-ID: <474D77EF.8090605@laotraesquina.com.ar> Date: Wed, 28 Nov 2007 09:15:11 -0500 From: Pablo Alcaraz User-Agent: Thunderbird 2.0.0.9 (Windows/20071031) MIME-Version: 1.0 To: pgsql-performance Subject: Re: TB-sized databases References: <4544e0330711260904g45d893a8ub1731e245aa8fc84@mail.gmail.com> <474B1407.3090607@laotraesquina.com.ar> <474B1B8C.1030505@gmail.com> <4544e0330711271218h56ce4cc3p280a9fefff24583d@mail.gmail.com> <1196197045.4246.1154.camel@ebony.site> <474CA2FA.2020201@laotraesquina.com.ar> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200711/347 X-Sequence-Number: 27762 Matthew wrote: > On Tue, 27 Nov 2007, Pablo Alcaraz wrote: > >> it would be nice to do something with selects so we can recover a rowset >> on huge tables using a criteria with indexes without fall running a full >> scan. >> > > You mean: Be able to tell Postgres "Don't ever do a sequential scan of > this table. It's silly. I would rather the query failed than have to wait > for a sequential scan of the entire table." > > Yes, that would be really useful, if you have huge tables in your > database. > Thanks. That would be nice too. I want that Postgres does not fall so easy to do sequential scan if a field are indexed. if it concludes that the index is *huge* and it does not fit in ram I want that Postgresql uses the index anyway because the table is *more than huge* and a sequential scan will take hours. I ll put some examples in a next mail. Regards Pablo