Begin forwarded message:
From: Yves Vindevogel <[EMAIL PROTECTED]>
Date: Mon 13 Jun 2005 17:45:19 CEST
To: Tom Lane <[EMAIL PROTECTED]>
Subject: Re: [PERFORM] Updates on large tables are extremely slow
Yes, but if I update one column, why should PG update 21 indexes ?
There's only one index affected !
On 13 Jun 2005, at 16:32, Tom Lane wrote:
Yves Vindevogel <[EMAIL PROTECTED]> writes:Met vriendelijke groeten,
rvponp=3D# vacuum verbose tblPrintjobs ;
INFO: vacuuming "public.tblprintjobs"
[ twenty-one different indexes on one table ]
Well, there's your problem. You think updating all those indexes is
free? It's *expensive*. Heed the manual's advice: avoid creating
indexes you are not certain you need for identifiable commonly-used
queries.
(The reason delete is fast is it doesn't have to touch the indexes ...
the necessary work is left to be done by VACUUM.)
regards, tom lane
Bien à vous,
Kind regards,
Yves Vindevogel
Implements
<<inline: Pasted Graphic 2.tiff>>
Met vriendelijke groeten,
Mail: [EMAIL PROTECTED] - Mobile: +32 (478) 80 82 91
Kempische Steenweg 206 - 3500 Hasselt - Tel-Fax: +32 (11) 43 55 76
Web: http://www.implements.be
<x-tad-smaller>
First they ignore you. Then they laugh at you. Then they fight you. Then you win.
Mahatma Ghandi.</x-tad-smaller>
Bien à vous,
Kind regards,
Yves Vindevogel
Implements
<<inline: Pasted Graphic 2.tiff>>
Mail: [EMAIL PROTECTED] - Mobile: +32 (478) 80 82 91
Kempische Steenweg 206 - 3500 Hasselt - Tel-Fax: +32 (11) 43 55 76
Web: http://www.implements.be
<x-tad-smaller>
First they ignore you. Then they laugh at you. Then they fight you. Then you win.
Mahatma Ghandi.</x-tad-smaller>
---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
