On Mon, 17 Dec 2007, Decibel! wrote:
Someone want to throw together some code that actually measures this? Maybe something that keeps a histogram of how many instructions take place per I/O request? If it turns out that counters do vary too much between CPUs, there might be ways that we can account for that.
I'd expect the easiest way to do a proof of concept here would be to use the Linux oprofile tool. That's already abstracted away the differences in hardware counters and provides a relatively simple interface to collect the data without getting bogged down with implementation there. Starting from scratch, going right to the hardware counters and building from there, is a big project--they've been hacking on oprofile for almost six years now and still aren't suggesting it's release quality yet.
-- * Greg Smith [EMAIL PROTECTED] http://www.gregsmith.com Baltimore, MD ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
