Re: Functions and Null Values

Thomas Swan <tswan@olemiss.edu> writes:
> From what I can gather the function only gets called when both values are 
> present and not when any of them are NULL.

It's sillier than that: the function does actually get called, and then
the return value is thrown away and replaced with a NULL.  This is an
inherent limitation of the old function-call interface.  It is fixed for
7.1 but I don't know of any good workaround for 7.0.* or before.

			regards, tom lane