On 2016-08-23 07:26:31 -0500, Kevin Grittner wrote: > On Tue, Aug 23, 2016 at 7:10 AM, Kevin Grittner <kgri...@gmail.com> wrote: > > On Mon, Aug 22, 2016 at 6:39 PM, Craig Ringer <cr...@2ndquadrant.com> wrote: > > >> Could you provide an example of a case where xacts replayed in > >> commit order will produce incorrect results? > > > > https://wiki.postgresql.org/wiki/SSI#Deposit_Report > > > > ... where T3 is on the replication target. > > I should, perhaps, have mentioned that the cases where this is are > problem are "eventually consistent" -- it's a matter of being able > to see a state that violates business rule invariants or where data > which is "locked down" according to one part of the database is > still changing. Such problems are prevented on a single database, > but would not be prevented on a logical replica where transactions > are applied in commit order. Given enough time, the replica would > eventually settle into a state without the anomalies, similar to > some other products with eventual consistency.
I've generally a bit of difficulty to see this as a significant problem for logical rep, as long as hot-standby, and crash-recovery in general, also has this problem... -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
