On Dec 16, 2011, at 7:25 PM, Bruce Momjian wrote:
> Robert Haas wrote:
>> On that theory, I'm inclined to think that's not really a problem.
>> We'll go nuts if we refuse to commit anything until it shows a
>> meaningful win on every imaginable workload, and it seems like this
>> can't really be worse than the status quo; any case where it is must
>> be some kind of artifact. We're better of getting rid of as much
>> ProcArrayLock contention as possible, rather than keeping it around
>> because there are corner cases where it decreases contention on some
>> other lock.
>
> Interesting conclusion, and it makes sense. Seems once this is applied
> we will have more places to look for contention improvements.
I also wonder how much this throws some previous performance tests into suspicion. If it's not uncommon for performance
improvementattempts to shift a bottleneck to a different part of the system and marginally hurt performance then we
mightbe throwing away good performance improvement ideas before we should...
--
Jim C. Nasby, Database Architect jim@nasby.net
512.569.9461 (cell) http://jim.nasby.net
