| From: | "Jonah H(dot) Harris" <jonah(dot)harris(at)gmail(dot)com> |
|---|---|
| To: | "Alvaro Herrera" <alvherre(at)commandprompt(dot)com> |
| Cc: | "Gregory Stark" <stark(at)enterprisedb(dot)com>, "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>, "Bruce Momjian" <bruce(at)momjian(dot)us>, "Josh Berkus" <josh(at)agliodbs(dot)com>, "Jaime Casanova" <jcasanov(at)systemguards(dot)com(dot)ec>, "Martijn van Oosterhout" <kleptog(at)svana(dot)org>, "Greg Stark" <greg(dot)stark(at)enterprisedb(dot)com>, "Pg Hackers" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Block-level CRC checks |
| Date: | 2008-12-15 17:37:20 |
| Message-ID: | 36e682920812150937q585df98etcf438685f6f4aa0f@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Mon, Dec 15, 2008 at 12:30 PM, Alvaro Herrera
<alvherre(at)commandprompt(dot)com> wrote:
>> How hard would it be to just take an exclusive lock on the page when setting
>> all these hint bits?
>
> I guess it will be intolerably slow then. If we were to say "we have
> CRC now, but if you enable it you have 1% of the performance" we will
> get laughed at.
Well, Oracle does tell users that enabling full CRC checking will cost
~5% performance overhead, which is reasonable to me. I'm not
pessimistic enough to think we'd be down to 1% the performance of a
non-CRC enabled system, but the locking overhead would probably be
fairly high. The problem is, at this point, we don't really know what
the impact would be either way :(
--
Jonah H. Harris, Senior DBA
myYearbook.com
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Josh Berkus | 2008-12-15 17:49:08 | Re: Fwd: [PATCHES] Auto Partitioning Patch - WIP version 1 |
| Previous Message | Joshua D. Drake | 2008-12-15 17:31:20 | Re: Block-level CRC checks |