From s.borse@direction.biz Thu Jul  10 09:12:34 2008
Received: from localhost (unknown [200.46.204.183])
	by postgresql.org (Postfix) with ESMTP id 7D84F65050C
	for <pgsql-admin-postgresql.org@postgresql.org>;
	Thu, 10 Jul 2008 06:12:34 -0300 (ADT)
Received: from postgresql.org ([200.46.204.86])
	by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024)
	with ESMTP id 07725-05 for <pgsql-admin-postgresql.org@postgresql.org>;
	Thu, 10 Jul 2008 06:12:25 -0300 (ADT)
X-Greylist: delayed 00:06:38.598846 by SQLgrey-1.7.6
Received: from ns1.aaaonlinux.net (NS1.AAAONLINUX.net [70.84.189.18])
	by postgresql.org (Postfix) with ESMTP id 4D7A265032E
	for <pgsql-admin@postgresql.org>; Thu, 10 Jul 2008 06:12:28 -0300 (ADT)
Received: (qmail 25752 invoked by uid 508); 10 Jul 2008 09:11:12 -0000
Received: from unknown (HELO direction.biz) (59.163.21.147)
	by ns1.aaaonlinux.net with SMTP; 10 Jul 2008 09:11:12 -0000
Received: from [172.16.2.20] ([172.16.2.20])
	(authenticated user s.borse@direction.biz)
	by direction.biz (direction.biz) (MDaemon PRO v9.0.0)
	with ESMTP id md50001972541.msg
	for <pgsql-admin@postgresql.org>; Thu, 10 Jul 2008 14:33:56 +0530
Subject: query optimization
From: Suresh Borse <s.borse@direction.biz>
Reply-To: s.borse@direction.biz
To: pgsql-admin@postgresql.org
Content-Type: multipart/alternative; boundary="=-muCmwfxQFEheGbnwD5h1"
Organization: DSS
Date: Thu, 10 Jul 2008 14:31:33 +0530
Message-Id: <1215680493.2113.26.camel@dss-052.dsslp.com>
Mime-Version: 1.0
X-Mailer: Evolution 2.10.3 (2.10.3-9.fc7) 
X-Authenticated-Sender: s.borse@direction.biz
X-Spam-Processed: direction.biz, Thu, 10 Jul 2008 14:33:56 +0530
	(not processed: spam filter heuristic analysis disabled)
X-MDRemoteIP: 172.16.2.20
X-Return-Path: s.borse@direction.biz
X-MDaemon-Deliver-To: pgsql-admin@postgresql.org
X-MDAV-Processed: direction.biz, Thu, 10 Jul 2008 14:33:57 +0530
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Spam-Status: No, hits=0.269 tagged_above=0 required=5 tests=AWL=0.268,
	HTML_MESSAGE=0.001
X-Spam-Level: 
X-Archive-Number: 200807/98
X-Sequence-Number: 29708


--=-muCmwfxQFEheGbnwD5h1
Content-Type: text/plain
Content-Transfer-Encoding: 7bit

Dear All,

I am facing very strange problem in postgres while executing the view.

When I execute the view some times it takes few milliseconds, sometimes
it take several seconds and some times doesn't execute.

I tried to troubleshoot using the explain plan method. But explain plan
also changes for each execution.

Can anybody help me for troubleshooting  and for resolving the
performance issue.


Thanks & Regards,
Suresh Borse



--=-muCmwfxQFEheGbnwD5h1
Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: 7bit

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 TRANSITIONAL//EN">
<HTML>
<HEAD>
  <META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=UTF-8">
  <META NAME="GENERATOR" CONTENT="GtkHTML/3.14.1">
</HEAD>
<BODY>
<FONT SIZE="2">Dear All,</FONT><BR>
<BR>
<FONT SIZE="2">I am facing very strange problem in postgres while executing the view.</FONT><BR>
<BR>
<FONT SIZE="2">When I execute the view some times it takes few milliseconds, sometimes it take several seconds and some times doesn't execute.</FONT><BR>
<BR>
<FONT SIZE="2">I tried to troubleshoot using the explain plan method. But explain plan also changes for each execution.</FONT><BR>
<BR>
<FONT SIZE="2">Can anybody help me for troubleshooting&nbsp; and for resolving the performance issue.</FONT><BR>
<BR>
<BR>
<FONT SIZE="2">Thanks &amp; Regards,</FONT><BR>
<FONT SIZE="2">Suresh Borse</FONT><BR>
<BR>
<BR>
</BODY>
</HTML>

--=-muCmwfxQFEheGbnwD5h1--




From julius@nsoft.lt Thu Jul  10 09:25:40 2008
Received: from localhost (unknown [200.46.204.183])
	by postgresql.org (Postfix) with ESMTP id C8153650548
	for <pgsql-admin-postgresql.org@postgresql.org>;
	Thu, 10 Jul 2008 06:25:40 -0300 (ADT)
Received: from postgresql.org ([200.46.204.86])
	by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024)
	with ESMTP id 20768-01 for <pgsql-admin-postgresql.org@postgresql.org>;
	Thu, 10 Jul 2008 06:25:31 -0300 (ADT)
X-Greylist: from auto-whitelisted by SQLgrey-1.7.6
Received: from vilnius.balt.net (vilnius.balt.net [195.14.170.14])
	by postgresql.org (Postfix) with ESMTP id BCF5C65052F
	for <pgsql-admin@postgresql.org>; Thu, 10 Jul 2008 06:25:33 -0300 (ADT)
Received: from nSoft.lt (unknown [217.117.29.29])
	by vilnius.balt.net (Postfix) with ESMTP id A8DA33A1311;
	Thu, 10 Jul 2008 12:25:29 +0300 (EEST)
Received: from [192.168.16.3] (unknown [192.168.16.3])
	by nSoft.lt (Postfix) with ESMTP id 12E15BEE07;
	Thu, 10 Jul 2008 12:53:20 +0000 (GMT)
Message-ID: <4875D589.1030107@nsoft.lt>
Date: Thu, 10 Jul 2008 12:25:29 +0300
From: Julius Tuskenis <julius@nsoft.lt>
User-Agent: Thunderbird 2.0.0.14 (Windows/20080421)
MIME-Version: 1.0
To: s.borse@direction.biz
CC: pgsql-admin@postgresql.org
Subject: Re: query optimization
References: <1215680493.2113.26.camel@dss-052.dsslp.com>
In-Reply-To: <1215680493.2113.26.camel@dss-052.dsslp.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Spam-Status: No, hits=0.166 tagged_above=0 required=5 tests=AWL=0.166
X-Spam-Level: 
X-Archive-Number: 200807/99
X-Sequence-Number: 29709

Hello, Suresh

Maybe its taking long for the first time, and then its faster? Did you 
noticed any circumstances under witch your query takes longer to execute?


Suresh Borse rašė:
> Dear All,
>
> I am facing very strange problem in postgres while executing the view.
>
> When I execute the view some times it takes few milliseconds, 
> sometimes it take several seconds and some times doesn't execute.
>
> I tried to troubleshoot using the explain plan method. But explain 
> plan also changes for each execution.
>
> Can anybody help me for troubleshooting  and for resolving the 
> performance issue.
>
>
> Thanks & Regards,
> Suresh Borse
>
>


-- 
Julius Tuskenis
Programavimo skyriaus vadovas
UAB nSoft
mob. +37068233050




From s.borse@direction.biz Thu Jul  10 09:50:17 2008
Received: from localhost (unknown [200.46.204.183])
	by postgresql.org (Postfix) with ESMTP id 2C25C65052F
	for <pgsql-admin-postgresql.org@postgresql.org>;
	Thu, 10 Jul 2008 06:50:17 -0300 (ADT)
Received: from postgresql.org ([200.46.204.86])
	by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024)
	with ESMTP id 41014-10 for <pgsql-admin-postgresql.org@postgresql.org>;
	Thu, 10 Jul 2008 06:49:58 -0300 (ADT)
X-Greylist: from auto-whitelisted by SQLgrey-1.7.6
Received: from ns1.aaaonlinux.net (NS1.AAAONLINUX.net [70.84.189.18])
	by postgresql.org (Postfix) with ESMTP id 98024650332
	for <pgsql-admin@postgresql.org>; Thu, 10 Jul 2008 06:50:01 -0300 (ADT)
Received: (qmail 23290 invoked by uid 508); 10 Jul 2008 09:55:26 -0000
Received: from unknown (HELO direction.biz) (59.163.21.147)
	by ns1.aaaonlinux.net with SMTP; 10 Jul 2008 09:55:25 -0000
Received: from [172.16.2.20] ([172.16.2.20])
	(authenticated user s.borse@direction.biz)
	by direction.biz (direction.biz) (MDaemon PRO v9.0.0)
	with ESMTP id md50001972626.msg
	for <pgsql-admin@postgresql.org>; Thu, 10 Jul 2008 15:18:05 +0530
Subject: Re: query optimization
From: Suresh Borse <s.borse@direction.biz>
Reply-To: s.borse@direction.biz
To: Julius Tuskenis <julius@nsoft.lt>
Cc: pgsql-admin@postgresql.org
In-Reply-To: <4875D589.1030107@nsoft.lt>
References: <1215680493.2113.26.camel@dss-052.dsslp.com>
	<4875D589.1030107@nsoft.lt>
Content-Type: multipart/alternative; boundary="=-rkT+VYTd7fJpDg7RTVFq"
Organization: DSS
Date: Thu, 10 Jul 2008 15:15:44 +0530
Message-Id: <1215683144.2113.35.camel@dss-052.dsslp.com>
Mime-Version: 1.0
X-Mailer: Evolution 2.10.3 (2.10.3-9.fc7) 
X-Authenticated-Sender: s.borse@direction.biz
X-Spam-Processed: direction.biz, Thu, 10 Jul 2008 15:18:05 +0530
	(not processed: spam filter heuristic analysis disabled)
X-MDRemoteIP: 172.16.2.20
X-Return-Path: s.borse@direction.biz
X-MDaemon-Deliver-To: pgsql-admin@postgresql.org
X-MDAV-Processed: direction.biz, Thu, 10 Jul 2008 15:18:07 +0530
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Spam-Status: No, hits=0.202 tagged_above=0 required=5 tests=AWL=0.201,
	HTML_MESSAGE=0.001
X-Spam-Level: 
X-Archive-Number: 200807/101
X-Sequence-Number: 29711


--=-rkT+VYTd7fJpDg7RTVFq
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit


Good Afternoon !!!

The view executes very faster for the first time.

When I execute the view again and again suddenly it gets slow or it gets
hang.

I have also traced the query plan but it changes for each execution.Can
we fix the query plan.

I have also tested the view on my test machine but the result was same.

The view contains multi-table joins.

Warm Regards,
Suresh Borse



On Thu, 2008-07-10 at 12:25 +0300, Julius Tuskenis wrote:

> Hello, Suresh
> 
> Maybe its taking long for the first time, and then its faster? Did you 
> noticed any circumstances under witch your query takes longer to execute?
> 
> 
> Suresh Borse rašė:
> > Dear All,
> >
> > I am facing very strange problem in postgres while executing the view.
> >
> > When I execute the view some times it takes few milliseconds, 
> > sometimes it take several seconds and some times doesn't execute.
> >
> > I tried to troubleshoot using the explain plan method. But explain 
> > plan also changes for each execution.
> >
> > Can anybody help me for troubleshooting  and for resolving the 
> > performance issue.
> >
> >
> > Thanks & Regards,
> > Suresh Borse
> >
> >
> 
> 

--=-rkT+VYTd7fJpDg7RTVFq
Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: 7bit

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 TRANSITIONAL//EN">
<HTML>
<HEAD>
  <META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=UTF-8">
  <META NAME="GENERATOR" CONTENT="GtkHTML/3.14.1">
</HEAD>
<BODY>
<BR>
<FONT SIZE="2">Good Afternoon !!!</FONT><BR>
<BR>
<FONT SIZE="2">The view executes very faster for the first time.</FONT><BR>
<BR>
<FONT SIZE="2">When I execute the view again and again suddenly it gets slow or it gets hang.</FONT><BR>
<BR>
<FONT SIZE="2">I have also traced the query plan but it changes for each execution.Can we fix the query plan.</FONT><BR>
<BR>
<FONT SIZE="2">I have also tested the view on my test machine but the result was same.</FONT><BR>
<BR>
<FONT SIZE="2">The view contains multi-table joins.</FONT><BR>
<BR>
<FONT SIZE="2">Warm Regards,</FONT><BR>
<FONT SIZE="2">Suresh Borse</FONT><BR>
<BR>
<BR>
<BR>
On Thu, 2008-07-10 at 12:25 +0300, Julius Tuskenis wrote:
<BLOCKQUOTE TYPE=CITE>
<PRE>
<FONT COLOR="#000000">Hello, Suresh</FONT>

<FONT COLOR="#000000">Maybe its taking long for the first time, and then its faster? Did you </FONT>
<FONT COLOR="#000000">noticed any circumstances under witch your query takes longer to execute?</FONT>


<FONT COLOR="#000000">Suresh Borse ra&#353;&#279;:</FONT>
<FONT COLOR="#000000">&gt; Dear All,</FONT>
<FONT COLOR="#000000">&gt;</FONT>
<FONT COLOR="#000000">&gt; I am facing very strange problem in postgres while executing the view.</FONT>
<FONT COLOR="#000000">&gt;</FONT>
<FONT COLOR="#000000">&gt; When I execute the view some times it takes few milliseconds, </FONT>
<FONT COLOR="#000000">&gt; sometimes it take several seconds and some times doesn't execute.</FONT>
<FONT COLOR="#000000">&gt;</FONT>
<FONT COLOR="#000000">&gt; I tried to troubleshoot using the explain plan method. But explain </FONT>
<FONT COLOR="#000000">&gt; plan also changes for each execution.</FONT>
<FONT COLOR="#000000">&gt;</FONT>
<FONT COLOR="#000000">&gt; Can anybody help me for troubleshooting  and for resolving the </FONT>
<FONT COLOR="#000000">&gt; performance issue.</FONT>
<FONT COLOR="#000000">&gt;</FONT>
<FONT COLOR="#000000">&gt;</FONT>
<FONT COLOR="#000000">&gt; Thanks &amp; Regards,</FONT>
<FONT COLOR="#000000">&gt; Suresh Borse</FONT>
<FONT COLOR="#000000">&gt;</FONT>
<FONT COLOR="#000000">&gt;</FONT>


</PRE>
</BLOCKQUOTE>
</BODY>
</HTML>

--=-rkT+VYTd7fJpDg7RTVFq--




From julius@nsoft.lt Thu Jul  10 10:39:13 2008
Received: from localhost (unknown [200.46.204.183])
	by postgresql.org (Postfix) with ESMTP id A9280650162
	for <pgsql-admin-postgresql.org@postgresql.org>;
	Thu, 10 Jul 2008 07:39:13 -0300 (ADT)
Received: from postgresql.org ([200.46.204.86])
	by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024)
	with ESMTP id 93950-08 for <pgsql-admin-postgresql.org@postgresql.org>;
	Thu, 10 Jul 2008 07:39:05 -0300 (ADT)
X-Greylist: from auto-whitelisted by SQLgrey-1.7.6
Received: from vilnius.balt.net (vilnius.balt.net [195.14.170.14])
	by postgresql.org (Postfix) with ESMTP id 818FE65015E
	for <pgsql-admin@postgresql.org>; Thu, 10 Jul 2008 07:39:08 -0300 (ADT)
Received: from nSoft.lt (unknown [217.117.29.29])
	by vilnius.balt.net (Postfix) with ESMTP id 0D6093A12BB;
	Thu, 10 Jul 2008 13:39:05 +0300 (EEST)
Received: from [192.168.16.3] (unknown [192.168.16.3])
	by nSoft.lt (Postfix) with ESMTP id 67078BEE07;
	Thu, 10 Jul 2008 14:06:55 +0000 (GMT)
Message-ID: <4875E6C9.3090706@nsoft.lt>
Date: Thu, 10 Jul 2008 13:39:05 +0300
From: Julius Tuskenis <julius@nsoft.lt>
User-Agent: Thunderbird 2.0.0.14 (Windows/20080421)
MIME-Version: 1.0
To: s.borse@direction.biz
CC: pgsql-admin@postgresql.org
Subject: Re: query optimization
References: <1215680493.2113.26.camel@dss-052.dsslp.com>	
	<4875D589.1030107@nsoft.lt>
	<1215683144.2113.35.camel@dss-052.dsslp.com>
In-Reply-To: <1215683144.2113.35.camel@dss-052.dsslp.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Spam-Status: No, hits=0.161 tagged_above=0 required=5 tests=AWL=0.161
X-Spam-Level: 
X-Archive-Number: 200807/102
X-Sequence-Number: 29712

Please send the "explain analyze YOUR_QUERY" output after first run and 
later. Also please mention platform and pg version you are using.


Suresh Borse rašė:
>
> Good Afternoon !!!
>
> The view executes very faster for the first time.
>
> When I execute the view again and again suddenly it gets slow or it 
> gets hang.
>
> I have also traced the query plan but it changes for each 
> execution.Can we fix the query plan.
>
> I have also tested the view on my test machine but the result was same.
>
> The view contains multi-table joins.
>
> Warm Regards,
> Suresh Borse
>
>
>
> On Thu, 2008-07-10 at 12:25 +0300, Julius Tuskenis wrote:
>> Hello, Suresh
>>
>> Maybe its taking long for the first time, and then its faster? Did you 
>> noticed any circumstances under witch your query takes longer to execute?
>>
>>
>> Suresh Borse rašė:
>> > Dear All,
>> >
>> > I am facing very strange problem in postgres while executing the view.
>> >
>> > When I execute the view some times it takes few milliseconds, 
>> > sometimes it take several seconds and some times doesn't execute.
>> >
>> > I tried to troubleshoot using the explain plan method. But explain 
>> > plan also changes for each execution.
>> >
>> > Can anybody help me for troubleshooting  and for resolving the 
>> > performance issue.
>> >
>> >
>> > Thanks & Regards,
>> > Suresh Borse
>> >
>> >
>>
>>
>>     


-- 
Julius Tuskenis
Programavimo skyriaus vadovas
UAB nSoft
mob. +37068233050




From scott.marlowe@gmail.com Thu Jul  10 15:49:45 2008
Received: from localhost (unknown [200.46.204.183])
	by postgresql.org (Postfix) with ESMTP id 2F7AE6509E9
	for <pgsql-admin-postgresql.org@postgresql.org>;
	Thu, 10 Jul 2008 12:49:45 -0300 (ADT)
Received: from postgresql.org ([200.46.204.86])
	by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024)
	with ESMTP id 09081-04-4 for
	<pgsql-admin-postgresql.org@postgresql.org>;
	Thu, 10 Jul 2008 12:49:39 -0300 (ADT)
X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6
Received: from yx-out-2324.google.com (yx-out-2324.google.com [74.125.44.29])
	by postgresql.org (Postfix) with ESMTP id AF407650162
	for <pgsql-admin@postgresql.org>; Thu, 10 Jul 2008 12:47:34 -0300 (ADT)
Received: by yx-out-2324.google.com with SMTP id 8so955652yxb.73
	for <pgsql-admin@postgresql.org>; Thu, 10 Jul 2008 08:47:30 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma;
	h=domainkey-signature:received:received:message-id:date:from:to
	:subject:cc:in-reply-to:mime-version:content-type
	:content-transfer-encoding:content-disposition:references;
	bh=eCXuunJ8NgPrRDXFKtQEtsOCSw2RHCaH/iYmECG4RPc=;
	b=rfu0KcYRBpCJ2izA7UlIGXTwhlS77zkXbfrKUQiLh70oTsw9LjpZ5IHL7GbTGH4gLB
	CIXpJln9zQsWeL9taARSTdR6Oz0DbRGh+OLoXAtjs1dEDFqFIn7fYmFm0GHr//OePsPV
	7tSRw4klwJ0Fdg4exd8xTu77zkUU29MHxzhAE=
DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma;
	h=message-id:date:from:to:subject:cc:in-reply-to:mime-version
	:content-type:content-transfer-encoding:content-disposition
	:references;
	b=G2J2Z0JfTq8IAMuHF9eXAuHq5fSmMAZ16Z0zuJuIvWo60p9Bevv08WP1Zg0jx/btVT
	tCz9IkiR8LVhVg6YLcN1Nz3FuTp9qD22jbNpBjlUcwTyi2BwmEfKTD1K+xLnuDEp0bhM
	DiC/Qit/uJGyy2dKS2s1QvlK0auhvXKzmAzbY=
Received: by 10.114.46.6 with SMTP id t6mr3191308wat.39.1215704849150;
	Thu, 10 Jul 2008 08:47:29 -0700 (PDT)
Received: by 10.114.130.17 with HTTP; Thu, 10 Jul 2008 08:47:29 -0700 (PDT)
Message-ID: <dcc563d10807100847y1d6f5f5ei4e1e380ecc4c3c24@mail.gmail.com>
Date: Thu, 10 Jul 2008 09:47:29 -0600
From: "Scott Marlowe" <scott.marlowe@gmail.com>
To: s.borse@direction.biz
Subject: Re: query optimization
Cc: "Julius Tuskenis" <julius@nsoft.lt>, pgsql-admin@postgresql.org
In-Reply-To: <1215683144.2113.35.camel@dss-052.dsslp.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
References: <1215680493.2113.26.camel@dss-052.dsslp.com>
	<4875D589.1030107@nsoft.lt>
	<1215683144.2113.35.camel@dss-052.dsslp.com>
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Archive-Number: 200807/105
X-Sequence-Number: 29715

On Thu, Jul 10, 2008 at 3:45 AM, Suresh Borse <s.borse@direction.biz> wrote:
>
> Good Afternoon !!!
>
> The view executes very faster for the first time.
>
> When I execute the view again and again suddenly it gets slow or it gets
> hang.
>
> I have also traced the query plan but it changes for each execution.Can we
> fix the query plan.
>
> I have also tested the view on my test machine but the result was same.
>
> The view contains multi-table joins.

Do you have different where clauses for each time you execute it?
That can certainly affect performance each time, if you're where
clause is gonna grab 99% of the view, you'll get a different plan than
if you have a where clause that selects 0.01% of the table.

So yeah, we need explain analyze of each type of query that's fast
slow, and if there are ANY differences between them we need to know.



From tgl@sss.pgh.pa.us Thu Jul  10 16:21:56 2008
Received: from localhost (unknown [200.46.204.183])
	by postgresql.org (Postfix) with ESMTP id 859AB65003C
	for <pgsql-admin-postgresql.org@postgresql.org>;
	Thu, 10 Jul 2008 13:21:56 -0300 (ADT)
Received: from postgresql.org ([200.46.204.86])
	by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024)
	with ESMTP id 41263-07 for <pgsql-admin-postgresql.org@postgresql.org>;
	Thu, 10 Jul 2008 13:21:51 -0300 (ADT)
X-Greylist: from auto-whitelisted by SQLgrey-1.7.6
Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130])
	by postgresql.org (Postfix) with ESMTP id 25F2F64FD42
	for <pgsql-admin@postgresql.org>; Thu, 10 Jul 2008 13:21:52 -0300 (ADT)
Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1])
	by sss.pgh.pa.us (8.14.2/8.14.2) with ESMTP id m6AGLixc009896;
	Thu, 10 Jul 2008 12:21:44 -0400 (EDT)
To: s.borse@direction.biz, "Julius Tuskenis" <julius@nsoft.lt>,
	pgsql-admin@postgresql.org
Subject: Re: query optimization 
In-reply-to: <dcc563d10807100847y1d6f5f5ei4e1e380ecc4c3c24@mail.gmail.com> 
References: <1215680493.2113.26.camel@dss-052.dsslp.com>
	<4875D589.1030107@nsoft.lt>
	<1215683144.2113.35.camel@dss-052.dsslp.com>
	<dcc563d10807100847y1d6f5f5ei4e1e380ecc4c3c24@mail.gmail.com>
Comments: In-reply-to "Scott Marlowe" <scott.marlowe@gmail.com>
	message dated "Thu, 10 Jul 2008 09:47:29 -0600"
Date: Thu, 10 Jul 2008 12:21:44 -0400
Message-ID: <9895.1215706904@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Archive-Number: 200807/106
X-Sequence-Number: 29716

On Thu, Jul 10, 2008 at 3:45 AM, Suresh Borse <s.borse@direction.biz> wrote:
>> The view executes very faster for the first time.
>> When I execute the view again and again suddenly it gets slow or it gets
>> hang.
>> The view contains multi-table joins.

Uh, how many joins?

If you're exceeding geqo_threshold then you would get plans with a
random component to them.  You might want to increase the threshold,
although planning time would probably go up.

Also, what PG version is this?

			regards, tom lane