Re: Query puts 7.3.4 on endless loop but 7.4beta5 is fine.

From: Greg Stark <gsstark(at)mit(dot)edu>
To: Rajesh Kumar Mallah <mallah(at)trade-india(dot)com>
Cc: Christopher Browne <cbbrowne(at)acm(dot)org>, pgsql-performance(at)postgresql(dot)org
Subject: Re: Query puts 7.3.4 on endless loop but 7.4beta5 is fine.
Date: 2003-10-30 18:18:05
Message-ID: 87znfid1ya.fsf@stark.dyndns.tv
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Rajesh Kumar Mallah <mallah(at)trade-india(dot)com> writes:

> -> Seq Scan on tickets main (cost=0.00..465.62 rows=1 width=164)
> Filter: ((effectiveid = id) AND (("type")::text = 'ticket'::text) AND (((status)::text = 'new'::text) OR ((status)::text = 'open'::text)))

This query has to read through every ticket in the system and check if the
current user has access to it? It seems like this isn't going to be a terribly
fast query no matter how you slice it.

One thing that might help keep its run-time from growing is a partial index
WHERE type = 'ticket' and (status = 'new' OR status = 'open')

(I'm not sure what the point of the effectiveid=id clause is)

That at least might help when 99% of your tickets are old closed tickets. But
it will still have to scan through every new and open ticket which on some
systems could be a large number.

--
greg

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