Re: visibility maps

From: "Pavan Deolasee" <pavan(dot)deolasee(at)gmail(dot)com>
To: "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: "Heikki Linnakangas" <heikki(dot)linnakangas(at)enterprisedb(dot)com>, "Zdenek Kotala" <Zdenek(dot)Kotala(at)sun(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: visibility maps
Date: 2008-12-17 13:57:46
Message-ID: 2e78013d0812170557u67a5894aua27bb5476f02e9dd@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Wed, Dec 17, 2008 at 7:11 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
>
> I think what you are suggesting is that we should set the visibility map
> bit while dead line pointers (tombstones) still remain. If that's what
> you meant it's a bad idea.

No, I'm not suggesting that. I understand the problem there. I was
merely explaining how HOT-prune may some time (when there are no DEAD
line pointers created) help us set the visibility bit early.

OTOH I think we can still set PD_ALL_VISIBLE page header flag even
when there are DEAD line pointers.

Thanks,
Pavan

--
Pavan Deolasee
EnterpriseDB http://www.enterprisedb.com

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2008-12-17 14:02:01 Re: visibility maps
Previous Message Tom Lane 2008-12-17 13:53:44 Re: [ADMIN] shared_buffers and shmmax