"Tambet Matiisen" <t.matiisen@aprote.ee> writes:
> I observed slowdowns when I declared SQL function as strict. There were
> no slowdowns, when I implmented the same function in plpgsql, in fact it
> got faster with strict, if parameters where NULL. Could it be
> side-effect of SQL function inlining? Is there CASE added around the
> function to not calculate it, when one of the parameters is NULL?
IIRC we will not inline a STRICT SQL function if the resulting
expression would not behave strict-ly. This is clearly a necessary rule
because inlining would change the behavior otherwise. But the test for
it is pretty simplistic: CASEs are considered not strict, period. So I
think you are measuring the difference between inlined and not-inlined.
I'd suggest just leaving off the STRICT if you are writing a SQL
function you hope to have inlined.
regards, tom lane
