On 2016-08-31 14:23:41 -0400, Tom Lane wrote: > Andres Freund <and...@anarazel.de> writes: > > On 2016-08-31 13:59:48 -0400, Tom Lane wrote: > >> You are ignoring the performance costs associated with eating 100x more > >> shared buffer space than necessary. > > > I doubt that's measurable in any real-world scenario. You seldomly have > > hundreds of thousands of sequences that you all select from at a high > > rate. > > If there are only a few sequences in the database, cross-sequence > contention is not going to be a big issue anyway.
Isn't that *precisely* when it's going to matter? If you have 5 active tables & sequences where the latter previously used independent locks, and they'd now be contending on a single lock. If you have hundreds of thousands of active sequences, I doubt individual page locks would become a point of contention. Andres -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
