On Thu, 2011-07-28 at 11:15 -0400, Robert Haas wrote: > On Thu, Jul 28, 2011 at 11:10 AM, Hannu Krosing <ha...@2ndquadrant.com> wrote: > > My main point was, that we already do synchronization when writing wal, > > why not piggyback on this to also update latest snapshot . > > Well, one problem is that it would break sync rep.
Can you elaborate, in what way it "breaks" sync rep ? > Another problem is that pretty much the last thing I want to do is > push more work under WALInsertLock. Based on the testing I've done so > far, it seems like WALInsertLock, ProcArrayLock, and CLogControlLock > are the main bottlenecks here. I'm focusing on ProcArrayLock and > CLogControlLock right now, but I am pretty well convinced that > WALInsertLock is going to be the hardest nut to crack, so putting > anything more under there seems like it's going in the wrong > direction. probably it is not just the WALInsertLock, but the fact that we have just one WAL. It can become a bottleneck once we have significant number of processors fighting to write in single WAL. > IMHO, anyway. > > -- > Robert Haas > EnterpriseDB: http://www.enterprisedb.com > The Enterprise PostgreSQL Company > -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers