Re: Pre-allocated free space for row updating (like PCTFREE) - Mailing list pgsql-hackers

From Satoshi Nagayasu
Subject Re: Pre-allocated free space for row updating (like PCTFREE)
Date
Msg-id 43156136.9040600@nttdata.co.jp
Whole thread Raw
In response to Re: Pre-allocated free space for row updating  (Simon Riggs <simon@2ndquadrant.com>)
Responses Re: Pre-allocated free space for row  (Hannu Krosing <hannu@skype.net>)
Re: Pre-allocated free space for row  (Simon Riggs <simon@2ndquadrant.com>)
List pgsql-hackers
Simon Riggs wrote:
>>4. Allow to repair fragmentation in each page.
>>
>>Because updates cause fragmentation in the page.
>>
>>So we need to keep large continuous free space in each page,
>>if we want to get more effective on PCTFREE feature.
> 
> 
> ...doesn't VACUUM already do that?

VACUUM generates a huge load because it repaires all pages
on the table file.

I think (more light-weight) repairing on a single page
is needed to maintain free space in the specific page.

-- 
NAGAYASU Satoshi <nagayasus@nttdata.co.jp>


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