Michael Paquier <mich...@paquier.xyz> wrote on 06/27/2019 11:17:10 PM:
> From: Michael Paquier <mich...@paquier.xyz> > To: Brad Nicholson <br...@ca.ibm.com> > Cc: Grigory Smolkin <g.smol...@postgrespro.ru>, pgsql- > gene...@lists.postgresql.org > Date: 06/27/2019 11:17 PM > Subject: [EXTERNAL] Re: Re: Enabling checksums on a streaming replica > > On Wed, Jun 26, 2019 at 02:08:19PM -0400, Brad Nicholson wrote: > > In testing, it doesn't appear to matter. I've ensured that I've generated > > some full page writes (confirmed via pg_waldump), and those apply > > fine. > > Full pages writes are first written from shared buffers to WAL, where > their checksums does not actually apply. When the WAL records are > read an applied, a full page image is recovered in shared buffers. > The checksum of the page would get updated once the shared buffer page > used is evicted and written back to disk. > So if all the checksums are being recalculated on the replica, this approach should be relatively safe, should it not? Assuming pg_checksums is doing the right thing (and it looks to me like it should be). Brad.
