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Metadata Management for the Web
by Curtis Dyreson, Michael Böhlen, and Christian S. Jensen
Curtis Dyreson
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The goal of this project is to investigate the use of right-angle data models for metadata. A right-angle data model is a data model that is (recursively) nested. The nested data model stores the metadata in a different dataspace from the data, and enables users to naturally combine constraints on both within a single query.

The relational datamodel is not quite a right angle data model. The system catalog, which contains schema information and other metadata, in most relational DBMS products is stored as a set of tables. But the system catalog tables are not in a different dataspace. A (privileged) user that queries for a list of all tables in the database will also see the list of system tables. Often the system tables have special names.

The AUCQL project extends the semistructured model of data with support for metadata. The metadata is stored as a semistructure within each edge label. AUCQL has been implemented as a research prototype, has a on-line demo, and there is a helpful tutorial on using it.

The METAXPath project recursively nests XPath data model trees to extend XPath to support metadata.


Curtis E. Dyreson, Michael H. Böhlen, and Christian S. Jensen © 2001. All rights reserved.
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