Teaching a Schema Translator to Produce O/R Views

This paper describes a rule-based algorithm to derive a relational schema from an extended entity-relationship model. Our work is based on an approach by Atzeni and Torlone in which the source EER model is imported into a universal metamodel, a series of transformations are performed to eliminate constructs not appearing in the relational metamodel, and the result is exported. Our algorithm includes novel features that are needed for practical object to relational mapping systems: First, it generates forward- and reverseviews that transform instances of the source model into instances of the target and back again. These views automate the object-to-relational (O/R) mapping. Second, it supports a flexible mapping of inheritance hierarchies to flat relations that subsumes and extends prior approaches. Third, it propagates incremental updates of the source model into incremental updates of the target. We prove the algorithm’s correctness and demonstrate its practicality in an implementa...

• Type: Conference
• Year: 2007
• Where: ER
• Authors: Peter Mork, Philip A. Bernstein, Sergey Melnik
• Keywords: ER 2007, Extended Entity-relationship Model, Source Eer Model, Source Model