Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> Heikki Linnakangas wrote:
>> Note that the function is immutable, and the argument in the query is a
>> constant. The planner simply runs the function and replaces the function
>> call with the result.
> The planner runs the function? Ok, neat -- I didn't know it did that.
See eval_const_expressions. This is absolutely no different from
reducing 1=1 to TRUE.
regards, tom lane