A transient hypergraph-based model for data access

Two major methods of accessing data in current database systems are querying and browsing. The more traditional query method returns an answer set that may consist of data values (DBMS), items containing the answer (full text), or items referring the user to items containing the answer (bibliographic). Browsing within a database, as best exemplified by hypertext systems, consists of viewing a database item and linking to related items on the basis of some attribute or attribute value. A model of data access has been developed that supports both query and browse access methods. The model is based on hypergraph representation of data instances. The hyperedges and nodes are manipulated through a set of operators to compose new nodes and to instantiate new links dynamically, resulting in transient hypergraphs. These transient hypergraphs are virtual structures created in response to user queries, and lasting only as long as the query session. The model provides a framework for general data access that accommodates user-directed browsing and querying, as well as traditional models of information and data retrieval, such as the Boolean, vector space, and probabilistic models. Finally, the relational database model is shown to provide a reasonable platform for the implementation of this transient hypergraph-based model of data access.