Skip site navigation (1) Skip section navigation (2)

Re: Query puts 7.3.4 on endless loop but 7.4beta5 is fine. [ with better indenting ]

From: Christopher Browne <cbbrowne(at)acm(dot)org>
To: pgsql-performance(at)postgresql(dot)org
Subject: Re: Query puts 7.3.4 on endless loop but 7.4beta5 is fine. [ with better indenting ]
Date: 2003-10-30 12:52:28
Message-ID: m33cdakhv7.fsf@wolfe.cbbrowne.com (view raw or flat)
Thread:
Lists: pgsql-performance
mallah(at)trade-india(dot)com (Rajesh Kumar Mallah) wrote:
> Can you please have a Look at the below and suggest why it
> apparently puts 7.3.4 on an infinite loop . the CPU utilisation of
> the backend running it approches 99%.

What would be useful, for this case, would be to provide the query
plan, perhaps via

  EXPLAIN [Big Long Query].

The difference between that EXPLAIN and what you get on 7.4 might be
quite interesting.

I would think it quite unlikely that it is truly an "infinite" loop;
it is rather more likely that the plan winds up being pretty bad and
doing something [a bunch of nested loops, maybe?] that run longer than
your patience will permit.
-- 
wm(X,Y):-write(X),write('@'),write(Y). wm('cbbrowne','acm.org').
http://www3.sympatico.ca/cbbrowne/lsf.html
Rules of the Evil Overlord #81. "If I am fighting with the hero atop a
moving platform, have disarmed him, and am about to finish him off and
he glances behind  me and drops flat, I too will  drop flat instead of
quizzically turning around to find out what he saw."
<http://www.eviloverlord.com/>

In response to

Responses

pgsql-performance by date

Next:From: Franco Bruno BorghesiDate: 2003-10-30 13:56:29
Subject: Re: Ignoring index on (A is null), (A is not null)
Previous:From: Cestmir HyblDate: 2003-10-30 11:34:15
Subject: Re: Ignoring index on (A is null), (A is not null) conditions

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group