Re: GUC for default heap fillfactor - Mailing list pgsql-hackers

From ITAGAKI Takahiro
Subject Re: GUC for default heap fillfactor
Date
Msg-id 20070809093433.60CA.ITAGAKI.TAKAHIRO@oss.ntt.co.jp
Whole thread Raw
In response to GUC for default heap fillfactor  ("Pavan Deolasee" <pavan.deolasee@gmail.com>)
Responses Re: GUC for default heap fillfactor  (Decibel! <decibel@decibel.org>)
List pgsql-hackers
"Pavan Deolasee" <pavan.deolasee@gmail.com> wrote:

> If HOT gets into 8.3, we might need a GUC to set database wide heap
> fillfactor to an appropriate value.

I have no objection to do that, but we will need other default values soon,
something like default_[heap|btree|hash|gist|gin]_fillfactor. Some of us
might feel it is mess to add random guc variables.

> HOT works much
> better if there is atleast one tuple worth of free space in each block.

I find it is more important. You say *number-of-tuples* is more suitable
unit for fillfactor than *percentage*. It might be good to reconsider the
unit when we add a database wide GUC parameter. It could be that there are
a tables with 80 bytes length of tuples (1%) and one with 800 bytes length
(10%) in the same database.

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center




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