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Thread: 'Scripting' with Java rather than Javascript?

  1. #1
    Join Date
    Sep 2005
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    Default 'Scripting' with Java rather than Javascript?

    Hi,


    I've recently been evaluating SQL Server Integration Services and have been impressed with its ability to let you write 'scripting' code in VB.Net which is then compiled - providing much better performance.



    I was therefore wondering if it would be possible/feasible to include similar functionality in Kettle - i.e., would it be possible to have a script transformation that allowed you to write script in Java and have it pre-compiled?



    Thanks,



    Lawrie

  2. #2
    Join Date
    Nov 1999
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    Default RE: 'Scripting' with Java rather than Javascript?


  3. #3
    Join Date
    Sep 2005
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    Default RE: 'Scripting' with Java rather than Javascript?

    Hi Matt,


    Sorry to bother you again, but I would be really greatful if you could provide some further clarification...



    > The javascript you write is already compiled to java byte-code and then executed. Sure, the performance is not native, but it's pre-compiled much like the VB code is compiled. There is nothing that prevents us from adding engines for other scripting languages like Python, Ruby, Groovy, etc.



    The reason for my original post was that I have noticed that using Javascript transformations seems to cause quite a dramatic speed reduction (compared to an overall transformation that doesn't involve any Javascript). SQL Server Integration Services doesn't seem to suffer the same kind of perfomance drop when using VB.Net in Script Transformation Components and I had therefore wrongly assumed that Javascript was being interpreted rather than compiled (whether down to Java byte-code or native binary).



    If the Javascript code is compiled down to Java byte-code, why is Javascript / Rhino performance so much worse than that of the built-in transormations that are written in Java? (Apologies if I am being a bit thick - I'm just really interested to know).



    And is there any way it would be possible to provide "scripting" functionality without the performance drop?



    Thanks in advance,



    Lawrie.

  4. #4
    Join Date
    Nov 1999
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    9,729

    Default RE: 'Scripting' with Java rather than Javascript?

    I'm completely guessing that IS is one big code generator and in that case it just incorporates the script.


    As a matter of policy, I never comment positively or negatively on any other ETL tool, close source or open source. I don't compare features either.
    This policy has saved me from useless endless discussions too many times to change it now. I really hope you understand my position in this regard.



    In the case of Javascript, even though it is compiled, there is still scripting going on.
    And, there has to be interfacing between java and the scripting engine. This in particular seems to be the main bottleneck for the Kettle implementation.



    Here is an article on scripting performance vs. java .



    As you can see from the benchmarks, Rhino is not doing so bad compared to the other scripting languages. It's one of the reasons I picked it. The other being that it is very wide spread and well documented.



    Matt

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