Re: Error correction for n_dead_tuples - Mailing list pgsql-patches

From Bruce Momjian
Subject Re: Error correction for n_dead_tuples
Date
Msg-id 200709260823.l8Q8NKa05660@momjian.us
Whole thread Raw
In response to Error correction for n_dead_tuples  (ITAGAKI Takahiro <itagaki.takahiro@oss.ntt.co.jp>)
List pgsql-patches
This patch is no longer needed.  We can revisit this during 8.4 to see
if it is still needed now that we have HOT.

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

ITAGAKI Takahiro wrote:
> Here is a patch discussed in
> http://archives.postgresql.org/pgsql-hackers/2007-02/msg00010.php
>
> Concurrent vacuum will save n_dead_tuples value at the beginning.
> Stats collector will be subtract the value from n_dead_tuples
> instead of setting it to zero. The statistics accuracy of n_dead_tuples
> will be better, especially just after finish of a vacuum.
>
> The behavior in VACUUM FULL is not changed because concurrent updates
> are not allowed during VACUUM FULL.
>
> Comments welcome.
>
> Regards,
> ---
> ITAGAKI Takahiro
> NTT Open Source Software Center

[ Attachment, skipping... ]

>
> ---------------------------(end of broadcast)---------------------------
> TIP 6: explain analyze is your friend

--
  Bruce Momjian  <bruce@momjian.us>          http://momjian.us
  EnterpriseDB                               http://www.enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +

pgsql-patches by date:

Previous
From: Tom Raney
Date:
Subject: Hash Index Build Patch
Next
From: Bruce Momjian
Date:
Subject: Re: Recalculating OldestXmin in a long-running vacuum