We have described in this report the Object-Protocol Model (OPM). OPM has been used to model several genomic databases. Such a database, regarding a large scale sequencing project for molecular biology laboratories, is presented in [Chen & Markowitz 96b].
OPM has constructs adapted from SDM. Some SDM constructs, such as subclass derivations and attribute derivations using set operations (except attribute union), have not been incorporated into OPM mainly because these constructs were not required for modeling the scientific applications we encountered, and because we decided to avoid unnecessary complexity.
OPM 4.x schemas can be mapped into relational schema definitions and queries. This mapping is described in [Chen & Markowitz 96a]. An OPM schema editor is vailable for specifying OPM schemas.
Currently, we are working on a schema retrofitting tool for reverse engineering relational database definitions into OPM 4.x schema definitions. Our future plans include implementing OPM on top of an object-oriented or object-relational DBMS and exploring using OPM for integrating heterogeneous database schemas.