Received: from localhost (unknown [200.46.204.183]) by developer.postgresql.org (Postfix) with ESMTP id 670A62E0047 for ; Mon, 7 Apr 2008 15:06:26 -0300 (ADT) Received: from developer.postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 45175-03 for ; Mon, 7 Apr 2008 15:06:23 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from mails1.interdominios.com (mails1.interdominios.com [89.248.97.42]) by developer.postgresql.org (Postfix) with ESMTP id 2FB5F2E0041 for ; Mon, 7 Apr 2008 15:06:22 -0300 (ADT) Received: (qmail 12185 invoked from network); 7 Apr 2008 20:06:21 +0200 Received: from www.sedifa.com (HELO sardina) (83.175.220.10) by basamcapital.com with SMTP; 7 Apr 2008 20:06:21 +0200 From: Albert Cervera Areny Organization: Sedifa, S.L. To: pgsql-performance@postgresql.org Subject: Re: performance using table partitions in Postgres 8.2.6 Date: Mon, 7 Apr 2008 20:06:14 +0200 User-Agent: KMail/1.9.7 References: <47FA527E.4020101@lbl.gov> In-Reply-To: <47FA527E.4020101@lbl.gov> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Message-Id: <200804072006.15114.albert@sedifa.com> X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200804/65 X-Sequence-Number: 29558 A Dilluns 07 Abril 2008, Janet Jacobsen va escriure: > no. of partitions constraint_exclusion off constraint_exclusion on > 2 0.597 ms 0.427 ms > 4 0.653 ms 0.414 ms > 8 0.673 ms 0.654 ms > 16 1.068 ms 1.014 ms > 32 2.301 ms 1.537 ms > > I expected that the query time would decrease as the number of > partitions increases, but that's not what I am seeing. I get better > results (0.29 ms) if I simply index DMID and don't use the partitions. I see really small times here so probably the overhead that partitioning=20 imposes isn't worth yet. Maybe with 50M rows it'll help, you could try=20 feeding those 50M tuples and test again. =2D-=20 Albert Cervera Areny Dept. Inform=E0tica Sedifa, S.L. Av. Can Bordoll, 149 08202 - Sabadell (Barcelona) Tel. 93 715 51 11 =46ax. 93 715 51 12 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =2E....................... AVISO LEGAL ............................ La presente comunicaci=F3n y sus anexos tiene como destinatario la persona a la que va dirigida, por lo que si usted lo recibe por error debe notificarlo al remitente y eliminarlo de su sistema, no pudiendo utilizarlo, total o parcialmente, para ning=FAn fin. Su contenido puede tener informaci=F3n confidencial o protegida legalmente y =FAnicamente expresa la opini=F3n del remitente. El uso del correo electr=F3nico v=EDa Internet no permite asegurar ni la confidencialidad de los mensajes ni su correcta recepci=F3n. En el caso de que el destinatario no consintiera la utilizaci=F3n del correo electr=F3nico, deber=E1 ponerlo en nuestro conocimiento inmediatamente. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =2E.......................... DISCLAIMER ............................. This message and its attachments are intended exclusively for the named addressee. If you receive this message in error, please immediately delete it from your system and notify the sender. You may not use this message or any part of it for any purpose. The message may contain information that is confidential or protected by law, and any opinions expressed are those of the individual sender. Internet e-mail guarantees neither the confidentiality nor the proper receipt of the message sent. If the addressee of this message does not consent to the use of internet e-mail, please inform us inmmediately. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =20