Andres Freund <and...@2ndquadrant.com> wrote: > On 2013-11-20 05:59:58 -0800, Kevin Grittner wrote:
>> I don't understand where that would make sense; especially since >> I thought that a database FREEZE followed by a checkpoint >> releases old clog space anyway. > > It only releases them up to the (cluster wide) xmin horizon. So > if there are older snapshots or prepared xacts around... So as long as there are no open transactions or prepared transactions on the master which started before the release with the fix is applied, VACUUM FREEZE would be guaranteed to work? Since I don't see how a non-prepared transaction would be running from before a minor release upgrade, that just means we have to make sure there are no prepared transactions from before the upgrade? -- Kevin Grittner EDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
