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--