Re: function(contants) evaluated for every row

Bruce Momjian <bruce@momjian.us> writes:
> Notice the to_date()'s were not converted to constants in EXPLAIN so
> they are evaluated for every row.  to_date() is marked STABLE.

> Is this something we should improve?

No.  This is per expectation.  Only IMMUTABLE functions can be folded to
constants in advance of the query.
        regards, tom lane