On 02.12.2010 11:02, Simon Riggs wrote:
The cause of the issue is that replay starts at one LSN and there is a delay until the RunningXacts WAL record occurs. If there was no delay, there would be no issue at all. In CreateCheckpoint() we start by grabbing the WAInsertLock and later recording that pointer as part of the checkpoint record. My proposal is to replace the "grab the lock" code with the insert of the RunningXacts WAL record (when wal_level set), so that recovery always starts with that record type.
Oh, interesting idea. But AFAICS closing the gap between acquiring the running-xacts snapshot and writing it to the log is sufficient, I don't see what moving the running-xacts record buys us. Does it allow some further simplifications somewhere?
-- 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
