Re: pow support for pgbench

Hi Fabien,

Sorry for the confusion, I wasn't aware that SQL pow changed types
depending on
the input value.

I've modified the function to match more closely the behaviour of SQL,
except
that 0^(negative) returns 'double inf'. Do you think there is any value in
raising an error instead?


On Mon, Nov 6, 2017 at 2:12 PM, Fabien COELHO <coelho@cri.ensmp.fr> wrote:

>
> Hello Raúl,
>
> I've fixed the documentation and added an ipow function that handles both
>> positive and negative ints, having 0^0 == 1 and 0^(negative) ==
>> PG_INT64_MAX
>> since that's what my glibc math.h pow() is returning.
>>
>
> From the comment:
>
>  * For exp < 0 return 0 except when the base is 1 or -1
>
> I think that it should do what POW does in psql, i.e.:
>
>  fabien=# SELECT POW(2, -2); # 0.25
>
> that is if exp < 0 the double version should be used, it should
> not return 0.
>
> Basically the idea is that the pgbench client-side version should behave
> the same as the SQL version.
>
> --
> Fabien.




-- 

*Raúl Marín Rodríguez*carto.com