Sub-element Indexing and Probabilistic Retrieval in the POSTGRES Database System

Most current information retrieval systems use boolean search methods to request and retrieve documents. While e ective for precise query speci cations, boolean search systems su er when the request is of a more general nature such as in a subject search request. If the query is too precise, the search may fail with no documents returned, however, if the query is too general, too many documents may be returned with only a few actually relevant. Moreover, the documents are not returned in an order to make them easy to evaluate. More advanced retrieval systems, such as probabilistic retrieval, are being explored to address some of these problems.