Describes a hierarchical text database model and defines an algebra based on concordance lists. The algebra is presented as a theoretical model to define both a conceptual schema for the database and search protocols for database implementation. Several retrieval examples are included. (19 references) (MES)

Introduces a hypertext data model for textual databases in which the text is divided into a syntactic structure, which describes the relationships of the text parts, and an access structure, which is generated from the syntactic structure by users' queries. Implementation considerations for the structuring component, retrieval component, and…

Describes an approximate document ranking process that uses a compact array of in-memory, low-precision approximations for document length. Combined with another rule for reducing the memory required by partial similarity accumulators, the approximation heuristic allows the ranking of large document collections using less than one byte of memory…