From: | Simon Riggs <simon(at)2ndQuadrant(dot)com> |
---|---|
To: | Greg Smith <greg(at)2ndquadrant(dot)com> |
Cc: | Jeff Davis <pgsql(at)j-davis(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: Enabling Checksums |
Date: | 2012-12-17 19:14:22 |
Message-ID: | CA+U5nM+fXBGj1eUr=p_cCb1hy0QaoEmge+YhL-u7=1nhsOO24A@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On 14 December 2012 20:15, Greg Smith <greg(at)2ndquadrant(dot)com> wrote:
> On 12/14/12 3:00 PM, Jeff Davis wrote:
>>
>> After some thought, I don't see much value in introducing multiple
>> instances of corruption at a time. I would think that the smallest unit
>> of corruption would be the hardest to detect, so by introducing many of
>> them in one pass makes it easier to detect.
>
>
> That seems reasonable. It would eliminate a lot of issues with reproducing
> a fault too. I can just print the impacted block number presuming it will
> show up in a log, and make it possible to override picking one at random
> with a command line input.
Discussing this makes me realise that we need a more useful response
than just "your data is corrupt", so user can respond "yes, I know,
I'm trying to save whats left".
We'll need a way of expressing some form of corruption tolerance.
zero_damaged_pages is just insane, much better if we set
corruption_tolerance = N to allow us to skip N corrupt pages before
failing, with -1 meaning keep skipping for ever. Settable by superuser
only.
--
Simon Riggs http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2012-12-17 19:29:21 | Re: Enabling Checksums |
Previous Message | Tom Lane | 2012-12-17 18:39:17 | Re: XLByte* usage |