On Thu, Mar 24, 2016 at 11:20 PM, Robert Haas <robertmh...@gmail.com> wrote: > On Thu, Mar 24, 2016 at 2:11 AM, Michael Paquier > <michael.paqu...@gmail.com> wrote: >> - SyncRepWaitForLSN(gxact->prepare_end_lsn); >> + SyncRepWaitForLSN(gxact->prepare_end_lsn, false); >> Isn't it important to ensure that a PREPARE LSN is applied as well on >> the standby with remote_apply? Say if an application prepares a >> transaction, it would commit locally but its LSN may not be applied on >> the standby with this patch. That would be a surprising behavior for >> the user. > > You need to wait for COMMIT PREPARED, but I don't see why you need to > wait for PREPARE itself.
Multi-master conflict resolution. Knowing in-time that a prepared transaction has been applied is useful on another node for lock conflicts resolution. Say a PRIMARY KEY insert is prepared, and we want to know at application level that its prepared state is visible everywhere. -- Michael -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers