Digital Equipment Corporation

Rex A Flynn

Peter G Anick

Bryan Alvey

Jeffrey D Brennan

David R Hanssen

Jeffrey M Robbins

A method and apparatus for providing an historical perspective into a database of information objects through an efficient method and apparatus for versioning information objects stored in a database as well as an index representative of the information objects is disclosed. The latest versions of each one of the information objects and each one of the entries in the index are maintained in the database. Partial earlier versions of each one of the information objects and each one of the index entries are stored with the latest versions. The partial versions contain only sufficient information about the differences between the earlier versions and the later ones so that any earlier version may be reconstructed. Identification tags are employed as unique identifiers for each one of the plurality of information objects and for different versions of the information objects. Through the exploitation of the relative time ordering of generated identification tags, an efficient index representation and method for performing historical queries is provided.

System for reconstructing prior versions of indexes using records

An information retrieval system including a plurality of indices representative of information stored in the information retrieval system and a dynamic lexicon is disclosed. The system includes memory having a database stored therein, the database being logically divided to include the plurality of indices, an information database having information objects stored therein and a dynamic lexicon which includes a plurality of data items and groups of data items that appear in the information database. A predetermined time variable represents the last time the plurality of indices were reindexed. After changes are made to the lexicon, a time stamp is attached to each one of the plurality of changes to the lexicon to indicate when the change was made to the lexicon. At some specified time interval later, the reindexing process is invoked. This process involves selecting a subset of the plurality of changes made to the lexicon after the predetermined time variable, locating all information objects in the information database that are affected by the plurality of changes to the lexicon, reindexing the portions of the plurality of indices representative of the information objects affected by the changes to the lexicon to reflect the changes in the lexicon, and then updating the predetermined time variable to indicate changes to the lexicon have been processed. The foregoing process is repeated until all changes to the lexicon after the predetermined time have been applied to the plurality of indices.

Method and apparatus for integrating a dynamic lexicon into a full-text

A method and apparatus that translates a natural language query into a Boolean expression to be used to search a database. The Boolean expression is displayed on a screen so that the user can alter the Boolean expression using a mouse or similar input device and re-execute the search. The manipulations performed by the user include moving terms of the query, changing the order in which query terms are evaluated, adding terms, deleting terms, and selecting alternate versions of terms.

Growing community of inventors

Belmont, MA, United States of America

Rex A Flynn