Re: Dead Space Map - Mailing list pgsql-hackers

From Hannu Krosing
Subject Re: Dead Space Map
Date
Msg-id 1141143150.3864.3.camel@localhost.localdomain
Whole thread Raw
In response to Re: Dead Space Map  (Alvaro Herrera <alvherre@commandprompt.com>)
List pgsql-hackers
Ühel kenal päeval, T, 2006-02-28 kell 10:16, kirjutas Alvaro Herrera:
> Hannu Krosing wrote:
> 
> > In the "big table with hotspots" case, I doubt that the win from
> > btbulkdelete will outweight having to scan 100000 index pages to get to
> > the 30 or 50 that can be bulkdeleted.
> 
> Remember that WAL traffic is fsync'ed, so it can be _much_ slower than
> anything else.

But it should need to be fsynced only once, at commit time, so if you
can clean up more than one page, you end up with many wal records, but
just one fsync.

-------------
Hannu




pgsql-hackers by date:

Previous
From: Hannu Krosing
Date:
Subject: Re: Dead Space Map
Next
From: "Jim C. Nasby"
Date:
Subject: Re: Dead Space Map