Computer system and method for data base indexing and information retrieval

摘要

A computer system and method for data base indexing and information retrieval. A number of keywords are selected and each record of a data base is searched to determine in which records each keyword appears. The central processing unit of the system then creates a vector for each keyword which identifies each record number of the data base where the keyword appears and numerically sorts the record numbers. A special bit processor next transforms each vector into a bit string that is identified by one of the keywords. The bit strings are returned to the central processing unit and are stored in secondary storage so as to form an index for the data base. To retrieve information, one or more keywords are input to the central processing unit. The input keywords are used by the central processing unit to identify the bit string for each keyword. The keywords may be logically joined using "AND," "OR" and/or "NOT" commands. Each bit string retrieved from the index is then sent to the special purpose bit processor, which combines the bit strings according to the particular command. The resultant bit string is transformed by the bit processor into a vector which is returned to the central processing unit and which then is used to identify the individual records which contain the combined keywords.