On Wed, Aug 10, 2016 at 12:26 PM, Greg Stark <st...@mit.edu> wrote: > Complexity like this makes it hard to implement other features such as > CSNs. IIRC this already bit hot standby as well. I think it would be a > big improvement if we had a clear, well defined commit order that was > easy to explain and easy to reason about when new changes are being > made.
And here I was getting concerned that there was no mention of "apparent order of execution" for serializable transactions -- which does not necessarily match either the order of LSNs from commit records nor CSNs. The order in which transactions become visible is clearly a large factor in determining AOoE, but it is secondary to looking at whether a transaction modified data based on reading the "before" image of a data set modified by a concurrent transaction. I still think that our best bet for avoiding anomalies when using logical replication in complex environments is for logical replication to apply transactions in apparent order of execution. -- 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
