I think these are very useful general-purpose mathematical functions. They're part of C99, and they're commonly included in other mathematical libraries, such as the python math module, so I think it's useful to make them available from SQL.
The error-handling for these functions seems to be a little trickier than most, so that might need further discussion.
Regards, Dean
I tried to review the patch without applying it. It looks good to me, but I have one notice: ERROR: value out of range: overflow. I think we need to add information about the available ranges in the error message
