Simon Riggs wrote: > On Wed, 2009-09-23 at 17:45 +0300, Heikki Linnakangas wrote: >> XactClearRecoveryTransactions() when we see a shutdown checkpoint, which >> clears all recovery locks. But doesn't that prematurely clear all locks >> belonging to prepared transactions as well? > > Much better to read your second post(s). :-) > > Yes, you have found a(nother) issue. This was the first one that gave me > pause to think of the answer. The locks currently aren't tracked as to > whether they are 2PC or not, so we would need to store that info also so > that we can selectively release locks later. > > Question: is it possible to do a fast shutdown when we have a prepared > transaction?
Yes. > Would it be better to take a different approach there for > prepared transactions? It seems strange to write a shutdown checkpoint > when the system isn't yet "clean". Hmm, I guess you could define prepared transactions as active backends from the shutdown point of view, and wait for them to finish. I can see one problem, though: Once you issue shutdown, fast or smart, we no longer accept new connections. So you can't connect to issue the ROLLBACK/COMMIT PREPARED anymore. Anyway, it would be a change from the current behavior, so it would be better to cope with prepared transactions in the standby. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
