| From: | Magnus Hagander <magnus(at)hagander(dot)net> |
|---|---|
| To: | Michael Paquier <michael(at)paquier(dot)xyz> |
| Cc: | Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr>, Andres Freund <andres(at)anarazel(dot)de>, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>, Stephen Frost <sfrost(at)snowman(dot)net>, Michael Banck <michael(dot)banck(at)credativ(dot)de>, Robert Haas <robertmhaas(at)gmail(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: Online verification of checksums |
| Date: | 2019-03-04 07:09:33 |
| Message-ID: | CABUevEz7a6ABBDKzZaEf=6P5LNmHNDNQVK70Hgq2scUKUTSW3w@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Mon, Mar 4, 2019, 04:10 Michael Paquier <michael(at)paquier(dot)xyz> wrote:
> On Sun, Mar 03, 2019 at 07:58:26AM +0100, Fabien COELHO wrote:
> > I agree that having a server function (extension?) to do a full checksum
> > verification, possibly bandwidth-controlled, would be a good thing.
> However
> > it would have side effects, such as interfering deeply with the server
> page
> > cache, which may or may not be desirable.
>
> In what is that different from VACUUM or a sequential scan? It is
> possible to use buffer ring replacement strategies in such cases using
> the normal clock-sweep algorithm, so that scanning a range of pages
> does not really impact Postgres shared buffer cache.
>
Yeah, I wouldn't worry too much about the effect on the postgres cache when
that is done. It could of course have a much worse impact on the os cache
or on the "smart" (aka dumb) storage system cache. But that effect will be
there just as much with a separate tool.
/Magnus
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Jamison, Kirk | 2019-03-04 07:17:06 | RE: pgbench - doCustom cleanup |
| Previous Message | Michael Paquier | 2019-03-04 06:54:46 | Re: [WIP] CREATE SUBSCRIPTION with FOR TABLES clause (table filter) |