On Mon, 2009-10-05 at 10:19 -0400, Tom Lane wrote: > Simon Riggs <si...@2ndquadrant.com> writes: > > I don't see how that helps at all. The objective of lock counters was to > > know if we can skip acquiring an LWlock on all lock partitions. This > > change keeps the lock counters yet acquires the locks we were trying to > > avoid. This change needs some justification since it is not a bug fix. > > [ scratches head ... ] Why is hot standby messing with this sort of > thing at all? It sounds like a performance optimization that should > be considered separately, and *later*.
Possibly. We have 3 suggested approaches: * Avoid taking LockPartition locks while we get info for Hot Standby during normal running, by means of a ref counting scheme (Simon) * Take the locks and implement a ref counting scheme (Heikki) * Take the locks, worry later (Tom) The middle ground seems pointless to me. I'm happy to go with simple lock-everything-for-now but it's pretty clear its going to be a annoying performance hit. If we do that we should put in a parameter to turn on/off so that those who will never use Hot Standby can avoid this completely. I'll wait for Heikki's thoughts before implementing anything. -- Simon Riggs www.2ndQuadrant.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
