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From "Knut Anders Hatlen (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (DERBY-6447) Use StrictMath for more functions in SYSFUN
Date Tue, 07 Jan 2014 18:48:06 GMT

    [ https://issues.apache.org/jira/browse/DERBY-6447?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13864529#comment-13864529
] 

Knut Anders Hatlen commented on DERBY-6447:
-------------------------------------------

Also, the implementations in SystemProcedures suffer from overflow problems. For example,
SystemProcedures.TANH() returns NaN if the argument is very high, which results in an error:

{noformat}
ij> values tanh(1.7E308);
1                       
------------------------
ERROR 22003: The resulting value is outside the range for the data type DOUBLE.
{noformat}

If StrictMath.tanh() had been used instead, it would have returned 1.0.

> Use StrictMath for more functions in SYSFUN
> -------------------------------------------
>
>                 Key: DERBY-6447
>                 URL: https://issues.apache.org/jira/browse/DERBY-6447
>             Project: Derby
>          Issue Type: Improvement
>          Components: SQL
>    Affects Versions: 10.11.0.0
>            Reporter: Knut Anders Hatlen
>            Priority: Minor
>
> Most of the functions in the SYSFUN schema use methods in java.lang.StrictMath directly.
A few of them use methods in SystemProcedures instead. Java 1.5 added more methods to StrictMath,
so it is now possible to make more of the functions use StrictMath and drop the implementation
in SystemProcedures:
> - LOG10 could use StrictMath.log10()
> - COSH could use StrictMath.cosh()
> - SINH could use StrictMath.sinh()
> - TANH could use StrictMath.tanh()



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