On 03/04/2013 12:19 PM, Greg Smith wrote: > On 3/3/13 10:52 PM, Craig Ringer wrote: >> I also suspect that at least in the first release it might be desirable >> to have an option that essentially says "something's gone horribly wrong >> and we no longer want to check or write checksums, we want a >> non-checksummed DB that can still read our data from before we turned >> checksumming off". > > I see that as being something that involves disabling the cluster-wide > flag that turns checksumming on, the one that is reported by > pg_controldata. I think it would have to be a one-way, system down > kind of change, which I think is fair given the ugly (but feasible) > situation you're describing. It would need to be something stronger > than a GUC. Once you start writing out pages without checksums, you're > back into the fuzzy state where some pages have them, others don't, > and there's no good way to deal with that yet.
Agreed, I was envisioning a one-way process where re-enabling checksums would involve be a re-initdb and reload. A DB restart seems perfectly reasonable, it's just a full dump and reload before they can get running again that I feel must be avoided. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
