Re: float output precision questions

Tom Lane wrote:
>
> Bottom line: if DBL_DIG=15 and the float arithmetic is binary, then
> there are some double values that require 17 displayed digits to
> distinguish, even though not all 16-digit numbers are distinct.
>
> So I retract my original proposal and instead suggest that we offer
> a switch to display either DBL_DIG or DBL_DIG+2 significant digits
> (and correspondingly increase the digits for float4). The DBL_DIG+2
> case should handle the need for exact dump/reload.

Nice. This will be good for number storage purposes.

Shall it be done with two parameters, 'DOUBLE_FORMAT' and
'SINGLE_FORMAT', with options 'SHORT' and 'LONG' controlling how the
sprintf's are done ?

Will someone from pg-people do it or shall I do it for you ?
As I said previously, I have seen the GUC stuff and it seem's ok for me
to do it. I really do not know if there are any restrictions on who
implements what respecting PostgreSQL.
Tomorrow we have an holyday in Portugal and I shall leave for the whole
week-end, but I can do it on monday.

Best regards,
Pedro M. Ferreira

>
> regards, tom lane
>
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--
----------------------------------------------------------------------
Pedro Miguel Frazao Fernandes Ferreira
Universidade do Algarve
Faculdade de Ciencias e Tecnologia
Campus de Gambelas
8000-117 Faro
Portugal
Tel./Fax: (+351) 289 800950 / 289 819403
http://w3.ualg.pt/~pfrazao