Re: Power cut and performance problem - Mailing list pgsql-sql

From Aftab Alam
Subject Re: Power cut and performance problem
Date
Msg-id 003601c64d62$20db1400$ec1010ac@aftabn463
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In response to Re: Power cut and performance problem  (Jeff Frost <jeff@frostconsultingllc.com>)
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Regards,





-----Original Message-----
From: pgsql-sql-owner@postgresql.org
[mailto:pgsql-sql-owner@postgresql.org]On Behalf Of Jeff Frost
Sent: Tuesday, March 21, 2006 9:19 PM
To: Daniel Caune
Cc: pgsql-sql@postgresql.org
Subject: Re: [SQL] Power cut and performance problem


On Tue, 21 Mar 2006, Daniel Caune wrote:

> For example, the execution of the following query is fast as it used to
> be (gslog_event_id is the primary key on gslog_event):
>
>  select max(gslog_event_id) from gslog_event;  (=> Time: 0.773 ms)
>
>
> while the following query is really slow (several minutes):
>
>  select min(gslog_event_id) from gslog_event; (index on the primary key
> is taken)
>
>
> I'm not a hardware expert at all, but I supposed that the whole
> performance would be degraded when a problem occurs with RAID disks.  Am
> I wrong?  Could it be something else?  Are there some tools that check
> the state of a PostgreSQL database?

You would be correct, a hardware problem should manifest itself on both
those
queries.  What is the explain analyze output of those two queries?  It's
possible you have a corrupt index on gslog_event.  If that's the case, a
reindex would likely remedy the problem.  Is postgres logging any errors?

--
Jeff Frost, Owner     <jeff@frostconsultingllc.com>
Frost Consulting, LLC     http://www.frostconsultingllc.com/
Phone: 650-780-7908    FAX: 650-649-1954

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