On 15 March 2017 at 15:42, Petr Jelinek <petr.jeli...@2ndquadrant.com> wrote:
> Thinking about this some more. Why can't we use the same mechanism > standby uses, ie, use xid to identify the 2PC? It pushes work onto the downstream, which has to keep an <xid,gid> mapping in a crash-safe, persistent form. We'll be doing a flush of some kind anyway so we can report successful prepare to the upstream so an additional flush of a SLRU might not be so bad for a postgres downstream. And I guess any other clients will have some kind of downstream persistent mapping to use. So I think I have a mild preference for recording the gid on 2pc commit and abort records in the master's WAL, where it's very cheap and simple. But I agree that just sending the xid is a viable option if that falls through. I'm going to try to pick this patch up and amend its interface per our discussion earlier, see if I can get it committable. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers