Re: Online enabling of checksums

On Mon, Mar 19, 2018 at 11:40 AM, Andrey Borodin <x4mmm(at)yandex-team(dot)ru>
wrote:

> Hi, Daniel!
>
> > 19 марта 2018 г., в 4:01, Daniel Gustafsson <daniel(at)yesql(dot)se>
> написал(а):
> >
> > Fixed in patch just posted in 84693D0C-772F-45C2-88A1-
> 85B4983A5780(at)yesql(dot)se
> > (version 5). Thanks!
>
>
> I've been hacking a bit in neighboring thread.
> And come across one interesting thing. There was a patch on this CF on
> enabling checksums for SLRU. The thing is CLOG is not protected with
> checksums right now. But the bad thing about it is that there's no reserved
> place for checksums in SLRU.
> And this conversion from page without checksum to page with checksum is
> quite impossible online.
>
> If we commit online checksums before SLRU checksums, we will need very
> neat hacks if we decide to protect SLRU eventually.
>
> What do you think about this problem?
>

One would be adjusted to work with the other, yes. It makes no sense to now
allow online enabling once SLRU protection is in there, and it doesn't make
sense for either of these patches to be blocking the other one for commit,
though it would of course be best to get both included.

--
Magnus Hagander
Me: https://www.hagander.net/ <http://www.hagander.net/>
Work: https://www.redpill-linpro.com/ <http://www.redpill-linpro.com/>