| From: | "Simon Riggs" <simon(at)2ndquadrant(dot)com> |
|---|---|
| To: | "ITAGAKI Takahiro" <itagaki(dot)takahiro(at)oss(dot)ntt(dot)co(dot)jp> |
| Cc: | "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>, <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: VACUUM and spoiling the buffer manager cache |
| Date: | 2007-03-01 09:09:01 |
| Message-ID: | 1172740142.3760.1087.camel@silverbirch.site |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Thu, 2007-03-01 at 11:00 +0900, ITAGAKI Takahiro wrote:
> "Simon Riggs" <simon(at)2ndquadrant(dot)com> wrote:
>
> > > > VACUUM's current behaviour is to take blocks it has touched and place
> > > > them on the head of the freelist, allowing them to be reused.
> > >
> > > No, it puts them at the tail of the freelist.
> >
> > That's a minor point because the freelist is mostly empty, so head ==
> > tail in 99.9% of cases.
>
> That's correct. Also, even if a VACUUM process collects some unused buffers
> into the freelist, other backends comsume all of them in a moment.
AFAICS the patch is useful and valid.
Please could we have some additional testers, so that we have a range of
opinion, rather than just my/EDB tests.
I'll submit further detailed tests after feature freeze, since right now
I have other things to do, but I'll return to this point again.
--
Simon Riggs
EnterpriseDB http://www.enterprisedb.com
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Gregory Stark | 2007-03-01 09:15:04 | Re: Packed short varlenas, what next? |
| Previous Message | Zeugswetter Andreas ADI SD | 2007-03-01 08:53:26 | Re: SOC & user quotas |