On Thu, 4 Jun 2009, Robert Haas wrote:
That's because this thread has altogether too much theory and altogether too little gprof.
But running benchmarks and profiling is actual work; that's so much less fun than just speculating about what's going on!
This thread reminds me of Jignesh's "Proposal of tunable fix for scalability of 8.4" thread from March, except with only a fraction of the real-world detail. There are multiple high-profile locks causing scalability concerns at quadruple digit high user counts in the PostgreSQL code base, finding them is easy. Shoot, I know exactly where a couple are, and I didn't have to think about it at all--just talked with Jignesh a couple of times, led me right to them. Fixing them without causing regressions in low client count cases, now that's the hard part. No amount of theoretical discussion advances that any until you're at least staring at a very specific locking problem you've already characterized extensively via profiling. And even then, profiling trumps theory every time. This is why I stay out of these discussions and work on boring benchmark tools instead.
-- * Greg Smith gsm...@gregsmith.com http://www.gregsmith.com Baltimore, MD -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
