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Date: Mon, 6 Aug 2007 02:54:52 -0700
From: "Sven Clement" <sven@dsign.lu>
To: "Heikki Linnakangas" <heikki@enterprisedb.com>
Subject: Re: Performance problems with large telemetric datasets on 7.4.2
Cc: "Tom Lane" <tgl@sss.pgh.pa.us>,
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Ok thanks everybody for the calrification, after all now I allready learned
something new... ;)

My employer is currently thinking about migration to 8.2.x because of your
feedback, so I think that the problem could be resolved... ;)

Thanks to everyone...

Sven Clement

2007/8/6, Heikki Linnakangas <heikki@enterprisedb.com>:
>
> Sven Clement wrote:
> > Partially I found that one in the PostgreSQL Documentation for the
> > 7.x.xversions under the command REINDEX where they claim that you
> > should run a
> > reindex under certain circumstances and for my comprehension this says
> that
> > with some access pattern (as ours (major writes / one big delete per
> day))
> > the index may be corrupted or otherwise not really useful.
>
> Up to 7.3, periodical REINDEX was needed to trim down bloated indexes.
> Since 7.4, empty index pages are recycled so that's no longer necessary.
> You can still end up with larger than necessary indexes in recent
> versions under unusual access patterns, like if you delete all but a few
> index tuples from each index page, but it's rare in practice. And it's
> not unbounded growth like in <= 7.3.
>
> In any case, the indexes won't become corrupt.
>
> --
>   Heikki Linnakangas
>   EnterpriseDB   http://www.enterprisedb.com
>



-- 
DSIGN.LU
Sven Clement
+352 621 63 21 18
sven@dsign.lu

www.dsign.lu

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Ok thanks everybody for the calrification, after all now I allready learned something new... ;)<br><br>My employer is currently thinking about migration to 8.2.x because of your feedback, so I think that the problem could be resolved... ;)
<br><br>Thanks to everyone...<br><br>Sven Clement<br><br><div><span class="gmail_quote">2007/8/6, Heikki Linnakangas &lt;<a href="mailto:heikki@enterprisedb.com">heikki@enterprisedb.com</a>&gt;:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Sven Clement wrote:<br>&gt; Partially I found that one in the PostgreSQL Documentation for the<br>&gt; 7.x.xversions under the command REINDEX where they claim that you<br>&gt; should run a<br>&gt; reindex under certain circumstances and for my comprehension this says that
<br>&gt; with some access pattern (as ours (major writes / one big delete per day))<br>&gt; the index may be corrupted or otherwise not really useful.<br><br>Up to 7.3, periodical REINDEX was needed to trim down bloated indexes.
<br>Since 7.4, empty index pages are recycled so that&#39;s no longer necessary.<br>You can still end up with larger than necessary indexes in recent<br>versions under unusual access patterns, like if you delete all but a few
<br>index tuples from each index page, but it&#39;s rare in practice. And it&#39;s<br>not unbounded growth like in &lt;= 7.3.<br><br>In any case, the indexes won&#39;t become corrupt.<br><br>--<br>&nbsp;&nbsp;Heikki Linnakangas<br>
&nbsp;&nbsp;EnterpriseDB&nbsp;&nbsp; <a href="http://www.enterprisedb.com">http://www.enterprisedb.com</a><br></blockquote></div><br><br clear="all"><br>-- <br><a href="http://DSIGN.LU">DSIGN.LU</a><br>Sven Clement<br>+352 621 63 21 18<br><a href="mailto:sven@dsign.lu">
sven@dsign.lu</a><br><br><a href="http://www.dsign.lu">www.dsign.lu</a>

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