Steve writes:

> I think Fred used to phrase it along the lines of "IMAGE is a DBMS, not a
> data management system."
>
> It was a cop-out when I first heard it years ago, and it's still a cop-out
> today. Validated data, enforced types, engine-guaranteed logical
integrity,
> and similar concepts are just as much an integral part of the "base data"
of
> an application as are the size of the "Order Number" field or the link
from
> an invoice number to the associated payment. If my data system allows me
to
> delete the record defining an inventory item while there are still
> outstanding orders asking for that item, that system has failed in one of
> its primary responsibilities. If it lets me enter "78 March 2001" into a
> date field (an easy "fat finger" typo for today's date), it hasn't done
its
> job.

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