craig@gpu.utcs.utoronto.ca (Craig Hubley) (05/14/91)
Well, since there's no comp.object.databases...
I am looking for information on object databases, especially those that
incorporate (or support as a value added product) a robust set of tools
for building active value knowledge bases. These are similar to constraint
based systems, less discrete than rule based systems, and with the right
tools a relational DB could also qualify. I'll clarify what I mean:
Essentially the knowledge base is written as responses to the values of a
number of key variables. Changing these variables causes changes that
propagate - in this it is similar to a constraint-based system. However,
the changes don't necessarily propagate to stabilize other values. It can
reach conclusions with minimal information if this provides enough certainty,
but will ask for more information (i.e. further tests) if it thinks present
evidence is inconclusive. In this it is like a rule-based system. In fact
with rules like "if Y < 5 test X", "if Y > 4 and Y < 11 say OK", and
"if Y > 10 test Z" you can model any value-based system as a set of rules,
but it becomes a real mess to manage. Similarly, if you want to write an
application that responds to values in tables, you could build such a system
relationally. But it is important to keep it semantically close to how the
actual domain experts think of it, and they think of it as active values.
Anyone with experience applying a database to this kind of problem, I would
much appreciate hearing from. The system is presently LISP-based, but LISP
is not a likely candidate if the system is re-engineered to use a new database.
Any tool vendor (or satisfied user) that has a tool to recommend, please
send me mail and I will summarize if there's enough interest. I am very
open to suggestions. If vendors are reading this, please feel free to add
me to your mailing list.
Sincerely,
Craig Hubley "...get rid of a man as soon as he thinks himself an expert."
Craig Hubley & Associates------------------------------------Henry Ford Sr.
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Craig Hubley "...get rid of a man as soon as he thinks himself an expert."
Craig Hubley & Associates------------------------------------Henry Ford Sr.
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