Schema Migration for Legacy Systems
Description:
This project which is in its initial phase involves the development of both
a theoretical framework and practical tools for supporting the migration of
database technology towards object-orientation. A start has been made on a
prototype migration workbench to use as a vehicle for validating the
research. At present the functionality of the tool is limited to the
automatic generation of an inheritance hierarchy from a set of relations.
[figure here]
Previous research in this area has been concentrated in two areas.
- On the reverse engineering of relational databases into Entity
Relationship (ER) models and more recently the extension of this into the
Enhanced Entity Relationship (EER) model [1-3].
- Work on relating the Relational and Object data models has also arisen as
a result of the development of object-oriented front ends to existing
relational systems [4-6].
These two research fronts go part of the way towards our goal of a system
to aid complete database migration but concentrate on meta-data translation
rather than the bulk data itself. They also focus on the reverse
engineering of the relational model and do not consider the issue of the
subsequent forward engineering of an object-oriented schema from the EER
model. Similarly it is only the relationship between the relational and
object models that are considered and this project will investigate the
possible inclusion of the network model within its framework. In addition,
the idea of a workbench to facilitate this process which is to be the
practical outcome of the research is not addressed in the literature.
- 1. Gray, W.A., G.N. Wikramanayake, and N.J. Fiddian. Assisting Legacy
Database Migration. in Legacy Information Systems - Barriers to Business
Process Re-Engineering. 94. IEE.
- 2. Chiang, R.H.L., T.M. Barron, and V.C. Storey, Reverse engineering
of relational databases: Extraction of an EER model from a relational
database. Data & Knowledge Engineering, 94. 12: p. 107-142.
- 3. Premerlani, W.J. and M.R. Blaha, An Approach for Reverse
Engineering of Relational Databases. Communications of the ACM, 94. 37(5):
p. 42-49.
- 4. Burleson, D.K., Mapping Object-oriented applications to Relational
Databases, in Object Magazine. 94, p. 50 - 55.
- 5. Fishman, D., D. Beech, and H. Cate, Iris: An Object-oriented
Database Management System. ACM Trans. on Office Information Systems, 87.
5(1): p. 48-69.
- 6. Hsieh, S. and C. Chang. Capturing the Object-Oriented Database
Model in Relational Form. in 17th Annual international Computer Software
and Applications Conf. 93. Pheonix: IEEE.
Lancaster Personnel:
Funding:
- University of Central Lancashire research studentship
Status: Under revision
Last revision: 3rd March 1995
Comments welcome.
Database Pages /
David Nichols
/ dmn@comp.lancs.ac.uk