sferriol <sylvain.ferriol@imag.fr> writes:
> for example
> 1) select ... where a and b;
> 2) select ... where b and a;
> 1 and 2 will use the same cpu time or not ?
They'll generate the same query plan, except possibly for the evaluation
order of a and b (assuming that those end up attached to the same plan
node in the first place). What that means for CPU time would depend on
what a and b are.
What are you trying to accomplish, exactly? Your question is
essentially useless to ask or answer as it stands, so you'll
need to readjust your thinking.
regards, tom lane