Re: How many digits are printed with double precision?

http://lmgtfy.com/?q=postgresql+documentation+extra_float_digits


On 03/23/11 17:24, Mathieu Dubois wrote:
> Hi Tom,
>
> Thanks for the very fast answer but what do you mean exactly by :
>
> "See extra_float_digits."
>
> I have found messages on the mailing list but it doesn't help (I don't
> want to recompile everything). Is there an option in some configuration
> file to set?
>
> Mathieu
> On 03/23/2011 10:02 PM, Tom Lane wrote:
>> Mathieu Dubois<mathieu.dubois@limsi.fr> writes:
>>> I have a double precision column in my DB (it's the time at which an
>>> image was taken expressed in second from UNIX epoch). When I query the
>>> value (SELECT time...) I get only 5 digits after the dot (while I
>>> /suppose/ there are 6 digits). I have the same result when using
>>> pgadmin. The results looks like the rounding of the desired time (which
>>> I know by the filename).
>> See extra_float_digits. Be aware that cranking that up produces digits
>> that are not 100% trustworthy. If you are expecting exact results of
>> more than 15 places, you likely shouldn't be using float arithmetic.
>>
>> regards, tom lane