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The OPM Query Language and Translator - Version 4.1
I-Min A. Chen, Anthony Kosky, Victor M. Markowitz, and Ernest Szeto
Data Management Research and Development Group
Information and Computing Sciences Division
Lawrence Berkeley National Laboratory
1 Cyclotron Road, Berkeley, CA 94720
June 1996
Abstract:
This document describes the Object-Protocol Model (OPM) Query
Language (OPM-QL) and Query Translator (OPM-QLT) for version 4.1
of OPM.
OPM is an object data model that supports
specifying scientific (e.g., molecular biology) databases and queries
in terms of objects, protocols (laboratory experiments), and attributes.
Attributes qualify objects and protocols, and take values
that are associated with system provided data types or are objects.
OPM is currently implemented on top of relational database management
systems (DBMSs). An OPM Schema Translator maps OPM schemas into
relational database schemas and SQL procedures, and generates
a metadata file with information regarding the correspondence of
OPM and DBMS elements.
OPM-QL 4.1 extends OPM-QL 4.0 with support for variables, selection
from multiple classes, and two types of projection results,
``get tuple'' and ``get object''.
OPM-QLT is based on the metadata file mentioned above,
maps OPM-QL queries into SQL queries and/or procedures, executes
these SQL queries and procedures, and returns the query results
structured in terms of OPM constructs.
OPM-QLT 4.1 has been entirely rewritten, rather than
being an extension of OPM-QLT 4.0.
Postscript version of this document
VMMarkowitz&lbl.gov
July 1st, 1996