entities with calculated fields

From: Aristedes Maniatis (ar..sh.com.au)
Date: Thu Feb 15 2007 - 05:54:46 EST

  • Next message: Juergen Saar: "Re: entities with calculated fields"

    We are very close to a release of our software but we've hit a
    performance problem in our approach to displaying a list of records.
    We are fetching a list of courses and for each one showing the count
    of enrolments. To do that, we are performing a second stored query to
    do a count which is proving to be too slow since it requires a second
    trip back to the database for each row.

    Is there a way to do this by creating runtime virtual entity which
    represents a database view including that count column? Or for that
    matter any other approach to this speed problem? Doing this as a raw
    SQL fetch would obviously be quite quick since we could do this in
    one SELECT statement including the embedded COUNT, but we'd rather a
    Cayenne friendly option.

    Ari Maniatis

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