Doug asks:
        >This discussion has also revolved around many issues, one being
        performance.
        >If Image were enhanced to include data validation, how much
overhead is
        >added to each and every transaction?

Each and every transaction would not require validation...the only time the
validation would be called is when the data was changed/added, if the
transaction was a read or delete, then there shouldn't be any validation
required.

        -----Original Message-----
        From:   Frank Gribbin [SMTP:[log in to unmask]]
        Sent:   Friday, March 09, 2001 9:49 AM
        To:     [log in to unmask]
        Subject:        Re: Expensive RDBM Systems (Oracle)

        The concern about overhead can be allied by placing a binary flag in
the
        IMAGE call, eg
        1 = validate using imbedded rules and
        0 = skip validation

        Frank Gribbin
        Potter Anderson & Corroon LLP


        On Thu, 8 Mar 2001 23:19:17 -0500, Doug Werth <[log in to unmask]>
wrote:

        >
        >This discussion has also revolved around many issues, one being
        performance.
        >If Image were enhanced to include data validation, how much
overhead is
        >added to each and every transaction? Do the current benchmarks use
        >previously validated data for input? Would Image truly be able to
compete
        >performance-wise if it had to validate each field?
        >
        >Theoretically it shouldn't add much overhead overall to an
application
        >whether the validation is done in Image or in a program that runs
on the
        >3000 when you add the aggregate CPU cost for the transaction
assuming the
        >following equation is true.
        >
        > App with validation + Image = Thin app. + Image with validation
        >
        >
        >But, if batch input is coming from a front end data entry system
where the
        >data has already been validated then Image would just add more
overhead to
        >each transaction.
        >
        >I'm still "on the fence" on this issue. But I am concerned about
the
        >performance impact on existing applications and it should be
weighed
        against
        >the benefits it would provide. A good data entry system will likely
be
        >validating data up front using business rules in a way that can
very
        >difficult for DBMS.
        >
        >Doug.
        >
        >Doug Werth                             Beechglen Development Inc.
        >[log in to unmask]                               Cincinnati, Ohio