Re: Float output formatting options

Tom Lane wrote:
> "Pedro M. Ferreira" <pfrazao@ualg.pt> writes:
> 
>>int extra_float4_digits, default 0, min -4, max 2
>>int extra_float8_digits, defualt 0, min -13, max 2
> 
> 
> I think a single setting extra_float_digits would be sufficient.

Ok. Assuming,

int extra_float_digits, default 0, min -13, max 2

If extra_float_digits==-13 and we are outputing a float4 this results in 
a negative value for FLT_DIG+extra_float_digits. I dont know if 
sprintf's behaviour is the same across different libraries for this 
situation.

Should I include the following to handle this case ?

if(extra_float_digits<-4)  sprintf(ascii, "%.*g", FLT_DIG-4, num);
else  sprintf(ascii, "%.*g", FLT_DIG+extra_float_digits, num);

> 
> 
>>Also, if we concluded that there is a need of 2 more digits, should'nt 
>>this be the default ?
> 
> 
> No.  pg_dump would want to bump it up on-the-fly.
> 
>             regards, tom lane
> 
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-- 
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Pedro Miguel Frazao Fernandes Ferreira
Universidade do Algarve
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