Karl Wright <kwright(at)metacarta(dot)com> writes:
> - At any given time, there are up to 100 of these operations going on at
> once against the same database.
It sounds like your hardware is far past "maxed out". Which is odd
since tables with a million or so rows are pretty small for modern
hardware. What's the CPU and disk hardware here, exactly? What do you
see when watching vmstat or iostat (as appropriate for OS, which you
didn't mention either)?
regards, tom lane