[jira] Commented: (DERBY-3063) Extend the system function mechanism to support functions with multiple arguments

["Kristian Waagan (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/DERBY-3063?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12526118 ] 

Kristian Waagan commented on DERBY-3063:
----------------------------------------

I have two initial questions regarding this issue:
 a) Is it worth the extra code to support functions with more than one argument?
    - Support for one or two can be implemented using static final variables.
    - Support for an arbitrary number of arguments must be done by creating the needed structures in a loop.
 
 b) Is it possible to get Derby to "automatically" allow for valid conversions?
     For instance, JDBC defines POWER(number, power) where 'power' is an integer. StrictMath has pow(double,double). How do I get Derby to convert the integer 'power' to a 'double' when passing the value to the Java function? (I'm in the context of system functions defined in a table - see DERBY-475).

Question a) arises because right now I don't see many functions that actually requires more than one argument (ATAN2 is one of them). Can these few functions easily be added and implemented in a different way?

I'm attaching a sample patch adding support for functions with arbitrary number of arguments. Optimizations can easily be done for the common case of one or two arguments.

> Extend the system function mechanism to support functions with multiple arguments
> ---------------------------------------------------------------------------------
>
>                 Key: DERBY-3063
>                 URL: https://issues.apache.org/jira/browse/DERBY-3063
>             Project: Derby
>          Issue Type: Improvement
>          Components: SQL
>    Affects Versions: 10.4.0.0
>            Reporter: Kristian Waagan
>            Priority: Minor
>
> Extend the existing functionality for adding Java functions to SQL to support functions with multiple arguments.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.