Results - Model Transformation

01 Jun 1996 updated

See also Model transformation section of the meeting presentation

This refers to the information exchange and model generation steps from PAM to CDM, CDM into PDM, PDM into DDL (and reverse engineering), and other possible model levels.

  1. All agree we need more visibility and control of CDM->PDM the transformation process. See typical detail issue:

      2. "We are finding the Generate Physical Model option in DataArchitect V5.0.2 is very confusing and unpredictable with its new Preserve Modification options.

      When an identifier is changed in the CDM, it will not always be changed in the PDM. We have not found any set of Preserve Modification check boxes which controls this behavior. See attached airline models.

      If a Reference is deleted in the physical, our experiments indicate that the only way for that Reference to be regenerated is if you turn off the Preserve graphics check box. This is completely unobvious, undocumented as far as we can tell, and makes no sense to us."

    The new V5.0 Preserve Modifications tab section offers some tantalizing hints of more granular control but, per above, does not behave as expected. Furthermore, even if it did the control is limited to certain properties which the product developers have chosen to offer.

    How about the concept of a matrix of object types (explodable to object instances) down the rows matched to properties across the columns? You could elect to preserve everything in the matrix or only table naming for specific tables.

  2. Some more ambitious tools (e.g., Bachman, Silverrun) provide object level mapping between model levels to track each object transformation (e.g., move a column; split a table horizontally or vertically; replicate). Is this feasable?
  3. We suggest user defined transformation rules to limit or prohibit transformation actions (e.g., split a table vertically; replicate a column set), These rules could be packaged in sets into user defined architectures or model behavior patterns.
  4. Add a browser to view and undo changes made in the PDM such as column renames, merged foreign keys, column reorders, table renames, or index restructuring.
  5. Elevate triggers and referential integrity options to a logical form to allow generating one logical model into multiple physica model. See also Results - Diagrams
  6. Provide bi-directional synchronization between conceptual, logical, and physical models and the target DBMS instance.

Where to go from here:

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