SQL/MDR: Query language for consistent access of metadata registries based on SQL3

This paper proposes a query language to consistently access metadata registries. In current, many metadata registries have been built in various fields. Because there is no access method to access the metadata registries in a standard manner, many management systems for them have been developed in various and different access methods. In this paper, we propose a metadata registry query language that allows us to access consistently all metadata registries in a standardized manner. The query language, SQL/MDR is an extension of SQL3, which is familiar to existing database managers. Consequently, the query language reduces the development cost of a metadata registry management system. And it also enables all metadata registries to be accessed in a consistent manner. "copy; Springer-Verlag 2004.