Re: Need help with 8.4 Performance Testing

[justin <justin@xxxxxxxxxxxxxxx>]

Tom Lane wrote:

Scott Carey <scott@xxxxxxxxxxxxxxxxx> writes:
  

Which brings this back around to the point I care the most about:
I/O per second will diminish as the most common database performance limiting factor in Postgres 8.4's lifetime, and become almost irrelevant in 8.5's.
Becoming more CPU efficient will become very important, and for some, already is.  The community needs to be proactive on this front.
This turns a lot of old assumptions on their head, from the database down through the OS and filesystem.  We're bound to run into many surprises due to this major shift in something that has had its performance characteristics taken for granted for decades.
    

Hmm ... I wonder whether this means that the current work on
parallelizing I/O (the posix_fadvise patch in particular) is a dead
end.  Because what that is basically going to do is expend more CPU
to improve I/O efficiency.  If you believe this thesis then that's
not the road we want to go down.

			regards, tom lane
  

What does the CPU/ Memory/Bus performance road map look like?

Is the IO performance for storage device for what ever it be, going to be on par with the above to cause this problem?

Once IO performance numbers start jumping up I think DBA will have the temptation start leaving more and more data in the production database  instead of moving it out of the production database. Or start consolidating databases onto fewer servers .  Again pushing more load onto the IO.