Re: Concurrent MERGE

> Hm?  Please explain what you're talking about.

Transaction A locks 1 and wants a lock on 2
Transaction B locks 2 and wants a lock on 3
Transaction C locks 3 and wants a lock on 1

I've never had the deadlock detector successfully deal with the above.
Let alone a 4-way.

> Not sure I believe this either; one deadlock kills one transaction.
> If you lose multiple transactions I think you had multiple deadlocks.

Deadlock termination kills *all* of the transactions involved in the
deadlock; what else could it do?  This is as opposed to serialization
failures, in which usually only one of the transactions involved fails.

--                                  -- Josh Berkus                                    PostgreSQL Experts Inc.
                        http://www.pgexperts.com