Displaying more than six digits from a real number

Started by Clodoaldo Pinto Netoover 21 years ago4 messagesgeneral
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#1Clodoaldo Pinto Neto
clodoaldo_pinto@yahoo.com.br

The 7.4.2 manual says the precision of a real number is 6 decimal digits.

Is it possible to force the display of more than six decimal digits of a real
number whithout using to_char() or casting?

Using 7.4.2, FC2.

create table test (f4 float4) without oids;
insert into test values (4877852);
select f4, to_char(f4, 'FM9999999'), cast(f4 as int)
from test;
f4 | to_char | f4
-------------+---------+---------
4.87785e+06 | 4877852 | 4877852

Clodoaldo Pinto

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#2Tom Lane
tgl@sss.pgh.pa.us
In reply to: Clodoaldo Pinto Neto (#1)
Re: Displaying more than six digits from a real number

Clodoaldo Pinto <clodoaldo_pinto@yahoo.com.br> writes:

The 7.4.2 manual says the precision of a real number is 6 decimal digits.
Is it possible to force the display of more than six decimal digits of a real
number

Perhaps the extra_float_digits runtime parameter is what you want?
(You are of course aware that there aren't really more than six
useful digits there... or if you're not, maybe you should stay away
from float and use numeric.)

regards, tom lane

#3Bruno Wolff III
bruno@wolff.to
In reply to: Clodoaldo Pinto Neto (#1)
Re: Displaying more than six digits from a real number

On Wed, Dec 01, 2004 at 20:25:28 -0300,
Clodoaldo Pinto <clodoaldo_pinto@yahoo.com.br> wrote:

The 7.4.2 manual says the precision of a real number is 6 decimal digits.

Is it possible to force the display of more than six decimal digits of a real
number whithout using to_char() or casting?

I think you can use the extra_float_digits GUC variable to do what you want.

#4Clodoaldo Pinto Neto
clodoaldo_pinto@yahoo.com.br
In reply to: Tom Lane (#2)
Re: Displaying more than six digits from a real number
 --- Tom Lane <tgl@sss.pgh.pa.us> escreveu: 

Clodoaldo Pinto <clodoaldo_pinto@yahoo.com.br> writes:

The 7.4.2 manual says the precision of a real number is 6 decimal digits.
Is it possible to force the display of more than six decimal digits of a
real number

Perhaps the extra_float_digits runtime parameter is what you want?
(You are of course aware that there aren't really more than six
useful digits there... or if you're not, maybe you should stay away
from float and use numeric.)

That is exactly what I wanted. Yes, I'm aware. But I wonder how is the 7th
digit right? At least with the few tests I did it was never wrong.

I will have to change that column to float8 but for now it is good enough.

Thanks

 --- Bruno Wolff III <bruno@wolff.to> escreveu: 

I think you can use the extra_float_digits GUC variable to do what you want.

Regards,
Clodoaldo Pinto

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