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Re: [ba-ohs-talk] Concept: Typed Versioning

On Mon, 25 Mar 2002, Eric Armstrong wrote:    (01)

>   1. Can we completely enumerate the class of link types, and be
>       certain there is no need for some application to create a new one
>       that others don't need?    (02)

No.    (03)

>          --if so, it would be nice if they were built in
>          --if not, it would be better if they were added by the application    (04)

I don't agree with these conclusions.  Make the link typing system
extensible.  Link type information is still stored in the system, but
users could define completely new ontologies of link types.    (05)

>   2. Can we be reasonably certain that the complete set of links
>       is required by all applications?    (06)

No.    (07)

>          --if so, it again makes sense to have it as part of the data engine
>             spec
>          --if not, applications could smaller, lighter engines without them    (08)

Again, I disagree with your conclusions.  You can support link types in
the system, but not require that all of them be stored in one particular
engine.  The underlying engines should be designed as distributed, not
monolithic systems.    (09)

>   3. Can the data engine provide profitable manipulations for those
>       link types, or do their semantics properly exist at a higher level?    (010)

That's an interesting question.  A link type has some implied semantics,
but the logic for those semantics could be stored at a higher level.  At
minimum, you may want to have link type-checking at a lower level.    (011)

>    4. Onions are a good design.    (012)

No argument here.    (013)

> Basically, that's my view on things at the moment. Specific information
> encountered during development or use could easily change that
> opinion, but I've tried to identify the assumptions that make me lean the
> way I do.    (014)

I agree.  I can be sold, but I want to see how the different alternatives
support different scenarios.  I have a Topic Maps groves property set
lying around somewhere; I need to revisit that and think about how it was
implemented.  But I'd like to see how other data languages (i.e. NODAL and
DL) model these things.    (015)

-Eugene    (016)

+=== Eugene Eric Kim ===== eekim@eekim.com ===== http://www.eekim.com/ ===+
|       "Writer's block is a fancy term made up by whiners so they        |
+=====  can have an excuse to drink alcohol."  --Steve Martin  ===========+    (017)