Accession Number : AD0687442

Title :   RELATIONAL DATA FILE: EXPERIENCE WITH A SYSTEM FOR PROPOSITIONAL DATA STORAGE AND INFERENCE EXECUTION,

Corporate Author : RAND CORP SANTA MONICA CALIF

Personal Author(s) : Levien,Roger E.

Report Date : APR 1969

Pagination or Media Count : 37

Abstract : An overview is given of the prototype Relational Data File, a computer data bank distinguished by the storage of data in a series of separate 'atoms' of one binary relational sentence each, and the ability to retrieve data not explicitly stored that can be inferred from stored data. The prototype RDF contains 70,000 sentences extracted from scientific and technical source items. Each sentence is encoded in four 36-bit computer words, with synonyms automatically translated to standard form and ambiguities flagged for manual correction. New entries in the synonymy/ambiguity dictionary update all stored data. Each accepted sentence is quadruplicated and stored in four subfiles by each of the key elements. A string dictionary decodes entries for output. Special retrieval language, INFEREX, allows retrieval through any inference scheme that can be expressed in the predicate calculus and set theory. The RDF structure seems well suited for very large data bases where new types of data are continually being added and other types removed and where data are incomplete (as in rapidly changing fields), redundant, or unpredictable. (Author)

Descriptors :   (*DATA PROCESSING, *INFORMATION RETRIEVAL), PROGRAMMING LANGUAGES, CODING, DATA STORAGE SYSTEMS

Subject Categories : Information Science
      Computer Programming and Software
      Computer Hardware

Distribution Statement : APPROVED FOR PUBLIC RELEASE