Re: using float4, I get incorrect value when select

On Sun, Oct 01, 2006 at 10:47:27PM -0400, Anibal David Acosta F. wrote:
> Hello, I have a table, with a float4 column, when I insert a new row and for
> example I use this value "5000542,5" in the column of type float4, the
> insert do OK, but when I select (select myColumn from myTable) I get the
> value "5000540" I don't know why.
>
> But if I cast to float8 (select cast(myColumn as float8) from myTable) I get
> the correct value ("5000542,5").

Do you understand the concept of floating point and the difference
between float4 and float8? Floating point throws away digits that it
doesn't have room to store, and with float4 that occurs after about 6
digits.

If you want to remember exact numbers, use numeric.

Have a nice day,
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> From each according to his ability. To each according to his ability to litigate.