Re: pg 8.1.3, AIX, huge box, painfully slow.

On Fri, 07 Apr 2006 15:56:52 -0700
"Luke Lonergan" <llonergan@greenplum.com> wrote:

> Seems like you're hitting a very small target in RAM with these semop
> calls. I wonder what part of the code is doing this - Tom would know
> better how to trace it, but the equivalent of oprofile output would
> be nice.

I'm happy to test whatever I can, but I simply don't know enough AIX to
be able to tell whether a similar kernel-level profiler is
available/possible.

> The other thing that I'd like to see is an evaluation of the memory
> access latency of this machine from Register to RAM.  I couldn't find
> a benchmarking tool that was UNIX friendly out there, maybe I'll
> write one real quick.  I suspect this machine has a heinous latency
> and a storm of semops to the same spot of RAM might be a far worse
> performance problem on this machine than on others...

Well, as I said to Tom, the machine is available for running tests
on :) If it helps us, and helps pg become more AIX friendly, then I'm
all for whatever needs done...

Cheers,
Gavin.