Re: How to optimize monstrous query, sorts instead of

From: "Michael Mattox" <michael(dot)mattox(at)verideon(dot)com>
To: "Rod Taylor" <rbt(at)rbt(dot)ca>
Cc: "Postgresql Performance" <pgsql-performance(at)postgresql(dot)org>
Subject: Re: How to optimize monstrous query, sorts instead of
Date: 2003-06-25 15:09:21
Message-ID: CJEBLDCHAADCLAGIGCOOIEKICKAA.michael.mattox@verideon.com
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With a slight correction (you had m & mx so I changed them to be all mx, I
hope this is what you intended) this query works. It's exactly the same
speed, but it doesn't give me the warnings I was getting:

NOTICE: Adding missing FROM-clause entry for table "monitorx"
NOTICE: Adding missing FROM-clause entry for table
"monitorstatus_statusitemsx"
NOTICE: Adding missing FROM-clause entry for table
"monitorstatusitemlistd8ea58a5x"

I never knew what those were from, I even searched Google trying to find out
and I couldn't understand it so I gave up. Thanks for pointing this out for
me, and thanks for fixing my query.

Michael

> -----Original Message-----
> From: pgsql-performance-owner(at)postgresql(dot)org
> [mailto:pgsql-performance-owner(at)postgresql(dot)org]On Behalf Of Rod Taylor
> Sent: Wednesday, June 25, 2003 4:28 PM
> To: michael(dot)mattox(at)verideon(dot)com
> Cc: Postgresql Performance
> Subject: Re: [PERFORM] How to optimize monstrous query, sorts instead of
>
>
> > I didn't notice that before, thanks for pointing that out. I just tried
> > adding monitorx.idx to the select and it ended up making my query take
> > several minutes long. Any ideas how I can fix this and keep my
> performance?
>
> By using it aliased and non-aliased (2 different references to the same
> table) you've caused it to join itself.
>
> Try this:
>
> SELECT m.idx
> , ms.averageconnecttimex AS ms_averageconnecttime
> , ms.averagedurationx AS ms_averageduration
> , ms.datex AS ms_date
> , ms.idx AS ms_id
> , ms.statusstringx AS ms_statusstring
> , ms.statusx AS ms_status
> , msi.actualcontentx AS msi_actualcontent
> , msi.connecttimex AS msi_connecttime
> , msi.correctcontentx AS msi_correctcontent
> , msi.datex AS msi_date
> , msi.descriptionx AS msi_description
> , msi.durationx AS msi_duration
> , msi.errorcontentx AS msi_errorcontent
> , msi.idx AS msi_id
> , msi.monitorlocationx AS msi_monitorlocation
> , msi.statusstringx AS msi_statusstring
> , msi.statusx AS msi_status
>
> FROM monitorstatusx AS ms
> , monitorstatusitemx AS msi
>
> , monitorx AS mx
> , monitorstatus_statusitemsx AS mssisx
> , monitorstatusitemlistd8ea58a5x AS litem
>
> WHERE ms.jdoidx = mssisx.jdoidx
> AND mssisx.statusitemsx = litem.jdoidx
> AND litem.statusitemlistx = msi.jdoidx
> AND mx.jdoidx = ms.monitorx
> AND ms.datex BETWEEN '2003-06-20 08:57:21.36'
> AND '2003-06-29 08:57:21.36'
> AND m.idx = 'M-TEST_1444-TEST_00_10560561260561463219352'
>
> ORDER BY ms.datex DESC;
>
> --
> Rod Taylor <rbt(at)rbt(dot)ca>
>
> PGP Key: http://www.rbt.ca/rbtpub.asc
>

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