Re: Checksums by default?

* Michael Paquier (michael(dot)paquier(at)gmail(dot)com) wrote:
> On Sat, Jan 21, 2017 at 7:39 PM, Magnus Hagander <magnus(at)hagander(dot)net> wrote:
> > Is it time to enable checksums by default, and give initdb a switch to turn
> > it off instead?
> >
> > I keep running into situations where people haven't enabled it, because (a)
> > they didn't know about it, or (b) their packaging system ran initdb for them
> > so they didn't even know they could. And of course they usually figure this
> > out once the db has enough data and traffic that the only way to fix it is
> > to set up something like slony/bucardo/pglogical and a whole new server to
> > deal with it.. (Which is something that would also be good to fix -- but
> > having the default changed would be useful as well)
>
> Perhaps that's not mandatory, but I think that one obstacle in
> changing this default is to be able to have pg_upgrade work from a
> checksum-disabled old instance to a checksum-enabled instance. That
> would really help with its adoption.

That's moving the goal-posts here about 3000 miles away and I don't
believe it's necessary to have that to make this change.

I agree that it'd be great to have, of course, and we're looking at if
we could do something like: backup a checksum-disabled system, perform a
restore which adds checksums and marks the cluster as now having
checksums. If we can work out a good way to do that *and* have it work
with incremental backup/restore, then we could possibly provide a
small-downtime-window way to upgrade to a database with checksums.

Thanks!

Stephen