Message-ID: <4E79E702.4090405@peak6.com>
Date: Wed, 21 Sep 2011 08:30:42 -0500
From: Shaun Thomas <sthomas@peak6.com>
Reply-To: <sthomas@peak6.com>
Organization: Peak6
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To: AI Rumman <rummandba@gmail.com>
CC: <pgsql-performance@postgresql.org>
Subject: Re: REINDEX not working for wastedspace
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On 09/21/2011 02:01 AM, AI Rumman wrote:

> Using the query http://wiki.postgresql.org/wiki/Show_database_bloat,
> I got the following result for a table:

God. I wish they would erase that Wiki page, or at least add a 
disclaimer. That query is no better than a loose estimate. Never, ever, 
ever depend on it for critical information about your tables. Ever.

Ever.

With that said, there are a lot of ways which can get the information 
you want. One is the pgstattuple contrib, the other is the 
pg_freespacemap contrib (though that didn't get really useful until 8.4 
and above).

Check out those documentation pages for usage info. More importantly, 
ignore the results of that query. It's wrong. If you've just reindexed, 
those indexes are about as small as they're ever going to be.

-- 
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 800 | Chicago IL, 60604
312-676-8870
sthomas@peak6.com

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