From: Thomas Kellerer <spam_eater@gmx.net>
To: pgsql-performance@postgresql.org
Subject: Re: Select * is very slow
Date: Mon, 08 Nov 2010 18:09:21 +0100
Message-ID: <ib9as0$a8s$1@dough.gmane.org> (raw)
In-Reply-To: <4CD7D89A02000025000373D8@gw.wicourts.gov>
References: <1289197016462-3254568.post@n5.nabble.com>
<4CD7D89A02000025000373D8@gw.wicourts.gov>
Kevin Grittner, 08.11.2010 18:01:
> "shaiju.ck"<shaiju.ck@gmail.com> wrote:
>
>> The table have 200 records now.
>> Select * from employee takes 15 seconds to fetch the data!!!
>> Which seems to be very slow.
>> But when I say select id,name from empoyee it executes in 30ms.
>> Same pefromance if I say select count(*) from emloyee.
>
> You haven't given nearly enough information for anyone to diagnose
> the issues with any certainty. Earlier responses have asked for
> some particularly important information, and I would add a request
> to see the output from `VACUUM VERBOSE employee;`. Beyond that, you
> might want to review this page for checks you can make yourself, and
> information which you could provide to allow people to give more
> informed advice:
Do you really think that VACCUM is the problem? If the OP only selects two columns it is apparently fast.
If he selects all columns it's slow, so I wouldn't suspect dead tuples here.
My bet is that there are some really large text columns in there...
He has asked the same question here:
http://forums.devshed.com/postgresql-help-21/select-is-very-slow-761130.html
but has also failed to answer the question about the table details...
Regards
Thomas
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