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From Mark Thornton <mthorn...@optrak.co.uk>
Subject Re: Double.NaN in table?
Date Wed, 19 Dec 2007 10:07:48 GMT
Andrew ``Bass'' Shcheglov wrote:
> On Dec 19, 2007 12:23 PM, Thomas Nielsen <Thomas.Nielsen@sun.com> wrote:
>   
>> Looking at the derby code on the main trunk, I see the exception is
>> intentional, as there is an explicit check for NaN values in
>> NumberDataType.normalizeDOUBLE().
>>
>> Not sure if this is another DB2 compatability issue/limitation or not.
>> Maybe someone with deeper knowledge can give more details on this?
>>     
>
>
> This is odd,
>
> for Oracle, for instance, fully supports IEEE 754 (since 10g):
>
> http://www.oracle.com/technology/sample_code/tutorials/jdbc10g/ieeedatatypes/files/IEEEDatatypes.pdf
> http://download.oracle.com/docs/cd/B14117_01/server.101/b10759/sql_elements003.htm
>   
A few more data points. PostgreSQL supports it, but MySQL does not (they 
claim it is not supported in the SQL standard).
SqlServer 2000 did allow NaN but with a host of bugs if you tried, SQL 
Server 2005 checks for NaN and rejects it. As far as I can remember 
versions of SQL Server prior to 2000 did not allow NaN.
My SQL Standard handbook (1992) contains no mention of any of the 
special floating point values. Odd given that IEEE arithmetic had been 
around for quite a while by that date.

Mark Thornton


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