On Tue, Jun 15, 2010 at 8:09 PM, Josh Berkus <j...@agliodbs.com> wrote: > >> I have yet to convince myself of how likely this is to occur. I tried >> to reproduce this issue by crashing the database, but I think in 9.0 >> you need an actual operating system crash to cause this problem, and I >> haven't yet set up an environment in which I can repeatedly crash the >> OS. I believe, though, that in 9.1, we're going to want to stream >> from WAL buffers as proposed in the patch that started out this >> thread, and then I think this issue can be triggered with just a >> database crash. > > Yes, but it still requires: > > a) the master must crash with at least one transaction transmitted to > the slave an not yet fsync'd
Bzzzzt. Stop right there. It only requires the master to crash with at least one *WAL record* written but not transmitted, not one transaction. And most WAL record types are not fsync'd immediately. So in theory I think that, for example, an OS crash in the middle of a big bulk insert operation should be sufficient to trigger this. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise Postgres Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
