Re: Offline enabling/disabling of data checksums

On Thu, Mar 14, 2019 at 3:28 PM Christoph Berg <myon(at)debian(dot)org> wrote:

> Re: Magnus Hagander 2019-03-14 <CABUevEx7QZLOjWDvwTdm1VM+mjsDm7=
> ZmB8qck7nDmcHEY5O5g(at)mail(dot)gmail(dot)com>
> > Are you suggesting we should support running with a master with checksums
> > on and a standby with checksums off in the same cluster? That seems..
> Very
> > fragile.
>
> The case "shut down master and standby, run pg_checksums on both, and
> start them again" should be supported. That seems safe to do, and a
> real-world use case.
>

I can agree with that, if we can declare it safe. You might need some way
to ensure it was shut down cleanly on both sides, I'm guessing.

Changing the system id to a random number would complicate this.
>
> (Horrible idea: maybe just adding 1 (= checksum version) to the system
> id would work?)
>

Or any other way of changing the systemid in a predictable way would also
work, right? As long as it's done the same on both sides. And that way it
would look different to any system that *doesn't* know what it means, which
is probably a good thing.

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