Re: Vertical inheritance

From: Mike Kienenberger (mkienen..mail.com)
Date: Mon May 31 2010 - 12:17:45 UTC

  • Next message: Andrus Adamchik: "Re: Vertical inheritance"

    I guess I'd prefer to at least have the ability to do explicit
    mapping, like the modeler currently supports for single-table.

    What you're suggesting could work, but we have at least one very deep
    and wide inheritance tree in our current app, and the performance hit
    of joining more than a hundred tables (so far) unnecessarily would
    kill us.

    On Mon, May 31, 2010 at 8:00 AM, Andrus Adamchik <andru..bjectstyle.org> wrote:
    >
    > On May 31, 2010, at 7:48 AM, Mike Kienenberger wrote:
    >
    >> I didn't completely understand the question, so I'm not sure if this
    >> answers it.
    >
    > I guess the question was whether we want this in Cayenne mapping in some
    > form:
    >
    >  ..nheritance(strategy = InheritanceType.JOINED)
    >
    > or guess the strategy from other mapping clues (the later is our current
    > approach). It was more of a discussion item on what are the benefits of
    > either approach.
    >
    >>..iscriminatorColumn(name="object_type")
    >
    > Actually my plan is to use OUTER joins in Cayenne SELECT queries, so entity
    > type will be determined from the presence of the non-null joined ID column
    > in the result set and explicit discriminator ("entity qualifier expression"
    > in Cayenne terms) won't be needed.
    >
    > Andrus
    >
    >



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