> Actually, referring down to later parts of this thread, why can't this
> optimisation be performed internally for built-in types? I understand the
> issue with aggregates over user-defined types, but surely optimising max()
> for int4, text, etc is safe and easy?
Sorry, missed the bit about user-defined functions. So I should have said
built-in functions operating over built-in types. Which does sound more
complicated, but anyone redefining max() is surely not in a position to seek
sympathy if they lose performance?