On Wed, Mar 13, 2019 at 12:40 PM Sergei Kornilov <sk@zsrv.org> wrote:
Hi
>> One new question from me: how about replication? >> Case: primary+replica, we shut down primary and enable checksum, and "started streaming WAL from primary" without any issue. I have master with checksums, but replica without. >> Or cluster with checksums, then disable checksums on primary, but standby think we have checksums. > > Enabling or disabling the checksums offline on the master quite clearly requires a rebuild of the standby, there is no other way (this is one of the reasons for the online enabling in that patch, so I still hope we can get that done -- but not for this version).
I mean this should be at least documented. Change system id... Maybe is reasonable
I think this is dangerous enough that it needs to be enforced and not documented.
Most people who care about checksums are also going to be having either replication or backup...
>> Also we support ./configure --with-blocksize=(not equals 8)? make check on HEAD fails for me. If we support this - i think we need recheck BLCKSZ between compiled pg_checksum and used in PGDATA > > You mean if the backend and pg_checksums is built with different blocksize? Yeah, that sounds like something which is a cheap check and should be done.
Yep
This one I could more live with it only being a documented problem rather than enforced, but it also seems very simple to enforce.
