On Sat, Dec 17, 2011 at 1:00 AM, Jim Nasby <j...@nasby.net> wrote: > I also wonder how much this throws some previous performance tests into > suspicion. If it's not uncommon for performance improvement attempts to shift > a bottleneck to a different part of the system and marginally hurt > performance then we might be throwing away good performance improvement ideas > before we should...
I think we are (mostly) OK on this point, at least as far as the work I've been doing. We've actually had a few previous instances of this phenomenon - e.g. when I first committed my fastlock patch, performance actually got worse if you had >40 cores doing read-only queries, because speeding up the lock manager made it possible for the spinlock protection SInvalReadLock to mess things up royally. Nevertheless, we got it committed - and fixed the SInvalReadLock problem, too. This one is/was somewhat more subtle, but I'm feeling pretty good about our chances of making at least some further progress in time for 9.2. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
