Received: from localhost (unknown [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id B494C2E002F for ; Tue, 25 Mar 2008 05:35:28 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-maia, port 10024) with ESMTP id 50739-08 for ; Tue, 25 Mar 2008 05:35:18 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.5 Received: from an-out-0708.google.com (an-out-0708.google.com [209.85.132.247]) by postgresql.org (Postfix) with ESMTP id 36BDF2E002D for ; Tue, 25 Mar 2008 05:35:21 -0300 (ADT) Received: by an-out-0708.google.com with SMTP id c36so715019ana.33 for ; Tue, 25 Mar 2008 01:35:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:mime-version:content-type; bh=BRRV72EkjHxukCxd1hMOYx1uM1NF07L+wfLiuHSKFdg=; b=GSE8G7XSL3udn+JK1MV7aD8c3IjDLNCRjMtd9y1x+8uQzO/V3Db45LUxWDOM336N52P8BX0mDvsFk5dM96iy8q7GTXve4HgdrA/QmV6ZbZsL5j71Fj9BLXnixDy8Ywydq2sO+Xt6uFy7JKvKj08uekKllhTK+4PL1r696sFLfJU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=message-id:date:from:to:subject:mime-version:content-type; b=F5WhT8GxaZd7NrCinFGAThCosTqwbks9bUAFQI3pIna4B999Nim2EZIjtWtAdUh6hUykR5iUDprvb03VGy+uWVo8dsH6mgbWF+6oMEUeU46C9+nj6+u6oo7ASSH91hZ+JMWnxSBpGQphHNcjd4KUEHKBxqgvWzpSG6TPhNmQ6eo= Received: by 10.100.41.8 with SMTP id o8mr21012915ano.13.1206434120577; Tue, 25 Mar 2008 01:35:20 -0700 (PDT) Received: by 10.100.105.20 with HTTP; Tue, 25 Mar 2008 01:35:20 -0700 (PDT) Message-ID: Date: Tue, 25 Mar 2008 14:05:20 +0530 From: "sathiya psql" To: pgsql-performance@postgresql.org Subject: postgresql is slow with larger table even it is in RAM MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_1827_22241845.1206434120566" X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200803/458 X-Sequence-Number: 29412 ------=_Part_1827_22241845.1206434120566 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Dear Friends, I have a table with 32 lakh record in it. Table size is nearly 700 MB, and my machine had a 1 GB + 256 MB RAM, i had created the table space in RAM, and then created this table in this RAM. So now everything is in RAM, if i do a count(*) on this table it returns 327600 in 3 seconds, why it is taking 3 seconds ????? because am sure that no Disk I/O is happening. ( using vmstat i had confirmed, no disk I/O is happening, swap is also not used ) Any Idea on this ??? I searched a lot in newsgroups ... can't find relevant things.... ( because everywhere they are speaking about disk access speed, here i don't want to worry about disk access ) If required i will give more information on this. ------=_Part_1827_22241845.1206434120566 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Dear Friends,
     I have a table with 32 lakh record in it. Table size is nearly 700 MB, and my machine had a 1 GB + 256 MB RAM, i had created the table space in RAM, and then created this table in this RAM.

    So now everything is in RAM, if i do a count(*) on this table it returns 327600 in 3 seconds, why it is taking 3 seconds ????? because am sure that no Disk I/O is happening. ( using vmstat i had confirmed, no disk I/O is happening, swap is also not used )

Any Idea on this ???

I searched a lot in newsgroups ... can't find relevant things.... ( because everywhere they are speaking about disk access speed, here i don't want to worry about disk access )

If required i will give more information on this.


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