Re: [HACKERS] pow support for pgbench

Michael Paquier <michael.paquier@gmail.com> writes:
> On Tue, Dec 5, 2017 at 5:38 AM, Robert Haas <robertmhaas@gmail.com> wrote:
>> I'm willing to commit any of the following things:
>> 
>> 1. A patch that adds an integer version of pow() but not a double version
>> 2. A patch that adds a double version of pow() but not an integer version
>> 3. A patch that adds both an integer version of pow() and a double
>> version of pow(), with the two versions having different names

> It seems to me that 1 and 2 have value on their own for the workloads
> tried to be emulated, so what you are suggesting in 3 looks good to
> me. Now why are two different function names necessary?

ISTM one key issue here is whether pgbench's expression language is
meant to model SQL (where we have function overloading) or C (where
there is no overloading).  I don't think we've really settled on a
fixed policy on that, but maybe now is the time.

If we do think that function overloading is OK, there remains the
question of when the typing is resolved.  I think Robert is objecting
to resolving at runtime, and I tend to agree that that's something
we'd regret in the long run.  It doesn't match either SQL or C.

			regards, tom lane