Ron Peacetree <rjpeace@earthlink.net> writes:
> 2= No optimal external sorting algorithm should use more than 2 passes.
> 3= Optimal external sorting algorithms should use 1 pass if at all possible.
A comparison-based sort must use at least N log N operations, so it
would appear to me that if you haven't got approximately log N passes
then your algorithm doesn't work.
regards, tom lane