Re: data_checksums enabled by default (was: Move --data-checksums to common options in initdb --help)

Greetings,

* Michael Banck (michael(dot)banck(at)credativ(dot)de) wrote:
> Am Mittwoch, den 06.01.2021, 13:08 -0800 schrieb Peter Geoghegan:
> > On Wed, Jan 6, 2021 at 1:04 PM Michael Banck <michael(dot)banck(at)credativ(dot)de> wrote:
> > > At least data_checksums=on for Azure Managed Postgres, Amazon RDS and
> > > Google Cloud SQL Postgres. It might not be on for all types (I just
> > > checked the basic one each earlier today), but I guess it is.
> >
> > So you tested this using "show data_checksums;" in psql in each case?
>
> Yes.
>
> > What does "show full_page_writes;" show you?
>
> It's also 'on' for all three (wal_log_hints is 'off' everywhere).

Well, given that data_checksums is 'on', then wal_log_hints is
implicitly 'on', of course.

Given the mention that maybe they've gone and modified PG underneath, it
might be fun to run your same tests against those platforms to see if
the amount of WAL generated is in line with what you're seeing for stock
PG with the same settings, assuming you can get to that level of
detailed information anyway (pretty sure some of them provide that, but
not sure if all of them do).

Thanks,

Stephen