Method and apparatus using run length encoding to evaluate a database

Abstract

The present invention provides a method and apparatus for generating a database search result. The creation of the search result is achieved by representing the subdocument lists of an inverted database with encoded bit strings. The encoded bit strings are space efficient methods of storing the correspondence between terms in the database and their occurrence in subdocuments. Logical combinations of these bit strings are then obtained by identifying the intersection, union, and/or inversion of a plurality of the bit strings. Since keywords for a database search can be identified by selecting the terms of the inverted database, the logical combinations of bit strings represent search results over the database. This technique for method for generating a search result is computationally efficient because computers combine bit strings very efficiently. Also, the search elements of the present invention are not just limited to keywords. The search elements also include types of fields (e.g., date or integer fields) or other extracted entities.

Dependencies are inferred from the claim text.