Scott Ambler Persistence Layer


EJB design: Scott Ambler Persistence Layer

  1. Scott Ambler Persistence Layer (5 messages)

    We are looking at implementing a persistence layer in a 3-tier app. I like the design that ambler presented in his papers at I especially like the support for adhoc queries and the support for multiple object manipulation. The only thing that makes me nervous is his suggestion to use dynamic sql.

    Does anybody have experience with this design. How much of a performance hit can I expect? I have implemented it on a small scale. But I am unsure about well it scales.



    Threaded Messages (5)

  2. Scott Ambler Persistence Layer[ Go to top ]

    I have not seen Scott's paper, but all commercial persistence layers use, at least AFAIK, dynamic SQL. So I don't think that you should expect to many problems from this design decision.

  3. Scott Ambler Persistence Layer[ Go to top ]

    Well, Have you Tried Toplink for Java which is the Product of WebGain.
    Maybe you can try the same.
  4. The use of dynamic versus static sql has negligible
    performance implications, and if you pay attention
    to how your sql is built the db engine can cache and
    reuse parsed queries anyway. (Of course if you
    run ad hoc queries then this does not apply, but then
    nothing else will help you either..)

  5. Thanks for the responses. Can you point me in the direction of papers or samples that have implemented dynamic sql in Java or EJB.


  6. Scott Ambler Persistence Layer[ Go to top ]

    I am aware of 2 opensource implementation of Ambler's
    framework. The one is Artyom Rudoy's "pl" software, the
    other is "Osage". I think you can find the links from
    Scot Ambler's page where you can dowload the original
    papaer from. The Home page is incze