On Wed, 2009-02-25 at 22:39 +0200, Heikki Linnakangas wrote: > When we take the snapshot of running transactions in the master, in > GetRunningTransactionData(), it only includes top-level xids and those > subxids that are in the subxid caches. Overflowed subxids are not > included. Isn't that a problem? When the standby initializes the > recovery procs using the running xacts information, pg_subtrans doesn't > isn't set for the overflowed xids, because that information is not > included in the WAL record. If you're lucky, the information is there > already, but we don't generally guarantee pg_subtrans to survive crash > or restart.
That is exactly the reason why we don't treat an overflowed snapshot as a valid starting point. -- 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
