Re: flattened prefetches

From: Cris Daniluk (cris.danilu..mail.com)
Date: Mon Oct 03 2005 - 17:11:41 EDT

  • Next message: Andrus Adamchik: "Re: flattened prefetches"

    On 10/3/05, Andrus Adamchik <andru..bjectstyle.org> wrote:
    > Yeah, joint prefetches are needed in case of flattened. Look at it
    > from the DB perspective - if there are two related tables and neither
    > of them has an FK to another one, you have to have a join somewhere
    > to figure it out. In Cayenne terms, person row snapshot doesn't have
    > enough info to figure out related city ObjectId.

    In some cases, I'd agree - though in other cases I would not. For
    example, if I query across the relationship by path
    (query.addPrefetch("toHouse.toCity")), then when I invoke
    person.getToCity, it should work.

    > query.addPrefetch(String); // Cayenne decides which one to use
    > query.addPrefetch(String, int type); // User decides which type to use
    >

    What would the deciding factor be? Currently, the resolver
    automatically converts joint prefetches to straight prefetches if the
    user does a dangerous query. Maybe it could be reversed so that its
    made into a joint prefetch if it *isn't* dangerous..



    This archive was generated by hypermail 2.0.0 : Mon Oct 03 2005 - 17:11:42 EDT