Re: visibility maps and heap_prune - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: visibility maps and heap_prune
Date
Msg-id 200901150140.n0F1exD12180@momjian.us
Whole thread Raw
In response to Re: visibility maps and heap_prune  ("Pavan Deolasee" <pavan.deolasee@gmail.com>)
Responses Re: visibility maps and heap_prune  (Pavan Deolasee <pavan.deolasee@gmail.com>)
List pgsql-hackers
Is this something for 8.4 CVS?

---------------------------------------------------------------------------

Pavan Deolasee wrote:
> On Mon, Dec 8, 2008 at 11:33 AM, Pavan Deolasee <pavan.deolasee@gmail.com>wrote:
> 
> >
> >
> > On Sat, Dec 6, 2008 at 8:08 PM, Heikki Linnakangas <
> > heikki.linnakangas@enterprisedb.com> wrote:
> >
> >>
> >> If you see a straightforward way, please submit a patch!
> >>
> >>
> > Will do that.
> >
> >
> 
> Here is a patch which implements this. The PD_ALL_VISIBLE flag is set if all
> tuples in the page are visible to all transactions and there are no DEAD
> line pointers in the page. The second check is required so that VACUUM takes
> up the page. We could slightly distinguish the two cases (one where the page
> requires vacuuming only because of DEAD line pointers and the other where
> the page-tuples do not require any visibility checks), but I thought its not
> worth the complexity.
> 
> Thanks,
> Pavan
> 
> -- 
> Pavan Deolasee
> EnterpriseDB     http://www.enterprisedb.com

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--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + If your life is a hard drive, Christ can be your backup. +


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