Re: Open issues for HOT patch - Mailing list pgsql-hackers

From Decibel!
Subject Re: Open issues for HOT patch
Date
Msg-id 20070918220811.GA95343@decibel.org
Whole thread Raw
In response to Re: Open issues for HOT patch  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Open issues for HOT patch
List pgsql-hackers
On Tue, Sep 18, 2007 at 11:32:52AM -0400, Tom Lane wrote:
> > Another option would be to prune whenever the free space goes
> > below table fillfactor and hope that users would set fillfactor so that
> > atleast one updated tuple can fit in the block. I know its not best to
> > rely on the users though. But it can be good hint.
>
> If default fillfactor weren't 100% then this might be good ;-).  But

Erik Jones and I were just talking about FILLFACTOR...

Is the plan to keep it at 100% with HOT? ISTM that's not such a great
idea, since it forces at least the first update (if not many more) to be
COLD.

I realize that ideally we'd probably want FILLFACTOR to take things like
average tuple size and average number of updates per page into account,
but for a first pass 90% would likely be a good compromise...
--
Decibel!, aka Jim C. Nasby, Database Architect  decibel@decibel.org
Give your computer some brain candy! www.distributed.net Team #1828

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