Greg Stark <gsstark@mit.edu> writes:
> Christopher Browne <cbbrowne@acm.org> writes:
>> Are you certain it's a linear system?
> If you just consider the guc parameters that tell postgres how long various
> real world operations take (all the *_cost parameters) then it's a linear
> system. It has to be.
No it doesn't. Think caching effects for instance. We do have cache
effects in the cost models, even though they are wrong as per my nearby
rant...
regards, tom lane
