Intensional Associations Between Data and Metadata

摘要

There is a growing need to associate a variety of metadata with the underlying data, but a simple, elegant approach to uniformly model and query both the data and the metadata has been elusive. In this paper, we argue that (1) the relational model augmented with queries as data values is a natural way to uniformly model data, arbitrary metadata and their associations, and (2) relational queries with a join mechanism augmented to permit matching of query result relations, instead of only atomic values, is an elegant way to uniformly query across data and metadata. We describe the architecture of a system we have prototyped for this purpose, demonstrate the generality of our approach and evaluate the performance of the system, in comparison with previous proposals for metadata management.