Re: data checksums

The penalty is not "considerable", but it is not completely trivial either.
But it's more on the trivial side. Part of the problem is that it is hard
to measure, as it is very workload dependent. As to why it is not the
default, Postgres is very careful and conservative by default, and not
everybody was convinced that enabling checksums is worth the tradeoff,
especially (IIRC) with the lack of real-world examples of people
discovering issues thanks to these checksums. So yes, please enable and
share with us if the checksums catch anything.

I think the argument is worth re-opening again, because (as far as I know),
all of the companies providing Postgres support, whether completely
cloud-managed, setting up a complex HA cluster, or just providing tuning
advice, have enabled checksums by default for many, many years. So a big +1
from me to finally making it the default. It's a de-facto default anyway at
this point.

Cheers,
Greg