DTD-to-DB SCHEMA

[lauzon at us.ibm.com]

A note that I got from Thomas Bergstraesser (Microsoft) about the merging
of OIM and MDIS ...

---------------------- Forwarded by Shawn Lauzon/Rochester/IBM on 12/16/98
03:00 PM ---------------------------


"Thomas Bergstraesser (Exchange)" <thomberg at exchange.microsoft.com> on
12/16/98 01:34:17 PM

To:   Shawn Lauzon/Rochester/IBM
cc:
Subject:  RE: DTD-to-DB SCHEMA





I do not monitor the XML alias so there is a high chance that I miss
something. If you feel this is of broader interest pls feel to forward it.

Your findings are correct.
- MDIS is not XML bases
- MDIS is a very core model on purpose so that it is easy to implement
- MDIS will merge into OIM (since it is covered by the more expressive OIM)
- OIM is a very rich model and described in UML so one needs to
  understand UML and get exposed to the modeling rules used

The OIM will be the way forward and we are working with the MDC
to get all the deliverables in place. One of the tasks is to structure
OIM so that one can use parts more easily. However UML will stay
with us so it might be a good time to look into this cool standard.

MDIS is completely covered by OIM and you should be able to get
a mapping MDIS->OIM from the MDC Web site. MDIS as standard
has not achieved widespread support since it has been outpaced
by Web-technologies like XML and the OIM as semantic definition.

So what is the way forward if you can not wait until Q1 '99? I
would determine the subset of elements in the OIM you want to
use and select the XML elements which represent them. If
you stick to the format you are ensured that you are compatible
with the MDC OIM released in '99 providing you with free import/export
with enterprise meta data management systems. Additionally if you
need to add descriptions of other meta data elements in future
you can add them in a compatible way.

Depending on your application it might be reasonable to invest the time
to deal with OIM to gain compatibility and extensibility in later stages.
However if you are developing a one shot app it might be overkill.
    - thomas


At 12:04 PM 12/16/98 -0600, lauzon at us.ibm.com wrote:
>Thanks for all the response I got from this note.  Two of these
>particularly look interesting.  One is the OIM from Microsoft that is
>described by Thomas Bergstraesser, and the other is the Metadata
>Interchange Specification (MDIS) from the Meta Data Coalition (MDC).
>
>The MDIS seems to be almost exactly what I'm looking for to describe
>relational databases.  Unfortunately it doesn't really seem to be in XML,
>although they do mention using XML to distribute these MDIS documents.
OIM
>has been submitted to the MDC to become a standard, but it seems overly
>complex for what we're trying to do, although that might be just because I
>haven't had enough exposure to it.  What I'm not sure about is how
>widespread support is for MDIS in the XML community, or if there is any
>thought about it whatsoever.  Or is the trend for a standard based upon
>OIM?
>
>Shawn Lauzon
>Department MMB - San Francisco Database Persistence
>email: lauzon at us.ibm.com
>phone: (507) 253-6966 T/L 553-6966
>


> -----Original Message-----
> From:   Thomas Bergstraesser (Exchange)
> Sent:   Tuesday, December 15, 1998 11:39 AM
> To:     'lauzon at us.ibm.com'
> Cc:     Andrew Layman
> Subject:     RE: DTD-to-DB SCHEMA
>
> Shawn,
> we have developed the Open Information Model (OIM) a set of over 200
types
> that describe meta data in the application development, database design,
> and data warehousing domain. Part of this model is a complete database
> schema model for relational, multidimensional, and legacy models.
>
> The OIM is described completely in UML and can be mapped onto different
> implementation technologies. The interchange of meta data described by
OIM
> uses XML and we generate DTDs directly from the UML model. The DTD
> provides the tags and structures to describe elements like schema, table,
> column as well as cross relationships to components or executables.
>
> We have announced recently that we will move the OIM and its XML
> Interchange Format to the Meta Data Coalition of which IBM is a council
> member. We are currently in the process of removing all Microsoft
specific
> information from the model in order to make it technology-independent and
> vendor-neutral. As its sounds this might be an ideal starting point for
> your efforts and provides you with the additional benefit that your
schema
> can be stored in many existing repositories and displayed by over 60
> modeling tools.
>
> Our Web site http://www.microsoft.com/repository should provide you with
> all the necessary information including a downloadable version of our
SDK.
> The SDK includes the UML model of the OIM, the DTD generator, and the
DTDs
> for all the different parts of the OIM as well as the necessary
> import/export utilities. Note that this is all still focussed on the
> Microsoft Repository technology.
>
> I hope this information is helpful for you and I could see significant
> benefits if you would be able to align your representation. Feel free to
> contact me if you have further questions or need more information.
>     - thomas
>

... thread truncated ...



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