On Thu, 2008-08-07 at 10:56 -0400, Alvaro Herrera wrote: > Simon Riggs wrote:
> > ii) have postmaster allow connections while Redo is taking place, as > one > > part of allowing query access to standby database > > is interesting and I'm sure it would be very welcome. Of course, it > is first necessary to be able to run transactions in true "read only" > mode, which perhaps is nowadays not so difficult given the work with > VXids. Maybe I am assuming that part is easier than I thought. Florian's contribution with the VXid work should not be understated. I was going to spread the setting of the global variable InRedo to all backends, so they would be able to answer the question IsInRedo(). Anybody attempting to assign a new TransactionId would check this and then exit with an ERROR. There would also be a check in XLogInsert(), in case the first case doesn't catch everything or everyone. Transactions would also run as read-only transactions to keep the front door locked. Anything else you think needs bolting down? -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
