Re: When/if to Reindex - Mailing list pgsql-performance

From Decibel!
Subject Re: When/if to Reindex
Date
Msg-id 20070808203554.GP20424@nasby.net
Whole thread Raw
In response to Re: When/if to Reindex  (Bill Moran <wmoran@collaborativefusion.com>)
Responses Re: When/if to Reindex  (Bill Moran <wmoran@collaborativefusion.com>)
List pgsql-performance
On Wed, Aug 08, 2007 at 03:27:57PM -0400, Bill Moran wrote:
> I've had similar experience.  One thing you didn't mention that I've noticed
> is that VACUUM FULL often bloats indexes.  I've made it SOP that
> after application upgrades (which usually includes lots of ALTER TABLES and
> other massive schema and data changes) I VACUUM FULL and REINDEX (in that
> order).

You'd be better off with a CLUSTER in that case. It'll be faster, and
you'll ensure that the table has optimal ordering.

> Lots of ALTER TABLEs seem to bloat the database size considerably, beyond
> what normal VACUUM seems to fix.  A FULL seems to fix that, but it appears
> to bloat the indexes, thus a REINDEX helps.

Hrm, are you sure that's still true? I just did an ALTER TABLE ... TYPE
and it created a new file, meaning no bloating.

> I would expect that setting fillfactor to 100 will encourage indexs to bloat
> faster, and would only be recommended if you didn't expect the index contents
> to change?

Yes.
--
Decibel!, aka Jim Nasby                        decibel@decibel.org
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)

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