On Sun, 2014-11-09 at 11:57 -0500, Steve Singer wrote: > The reason why Jim and myself are asking for the LSN and not just the > timestamp is that I want to be able to order the transactions. Jim > pointed out earlier in the thread that just ordering on timestamp allows > for multiple transactions with the same timestamp. > > Maybe we don't need the entire LSN to solve that. If you already have > the commit timestamp maybe you only need another byte or two of > granularity to order transactions that are within the same microsecond.
There is no guarantee that a commit with later LSN has a later timestamp. There are cases where the clock could move significantly backwards. A robust solution to storing transaction commit information (including commit order) in a way that can be referenced from other tables, can be loaded to another cluster, and survives crashes would be a great feature. But this feature doesn't have those properties. - Anssi -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers