Thread: float value is rounded

Hello

I was surprised with rounding relative not big value. Is it correct?

postgres=# select 499188.546875::real;float4
────────499189
(1 row)

regards

Pavel Stehule

Pavel Stehule <pavel.stehule@gmail.com> writes:
> I was surprised with rounding relative not big value. Is it correct?

You do realize float4 has only 6 decimal digits of precision?
        regards, tom lane

2009/11/25 Tom Lane <tgl@sss.pgh.pa.us>:
> Pavel Stehule <pavel.stehule@gmail.com> writes:
>> I was surprised with rounding relative not big value. Is it correct?
>
> You do realize float4 has only 6 decimal digits of precision?
>

To today I though so float4 is more practical :).

I am smarter now
Pavel

>                        regards, tom lane
>

On Wed, Nov 25, 2009 at 07:46:11PM +0100, Pavel Stehule wrote:
> 2009/11/25 Tom Lane <tgl@sss.pgh.pa.us>:
> > Pavel Stehule <pavel.stehule@gmail.com> writes:
> >> I was surprised with rounding relative not big value. Is it
> >> correct?
> >
> > You do realize float4 has only 6 decimal digits of precision?
> >
> 
> To today I though so float4 is more practical :).

Floats have never been safe with respect to operations like =, and
won't become so.

Cheers,
David.
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