Accession Number : ADD007480

Title :   Key-to-Address Transformations.

Descriptive Note : Patent Application,

Corporate Author : DEPARTMENT OF THE ARMY WASHINGTON DC

Personal Author(s) : Connell,John B

Report Date : 05 May 1980

Pagination or Media Count : 48

Abstract : Storage or retrieval of a record from computer storageor memory is generally accomplished by scanning, searching, or direct addressing. Scanning a file of records to retrieve one particular record requires comparing its key with the key of one record after another until a match is found. Searching a file requires a proper organization of the records. Direct addressing involves assigning each record to a bin or bucket location (which is large enough to contain one or more records). The address of the bin is determined by means of a key-to-address, randomizing, or hashing transformation. Direct addressing provides the most rapid means of accessing a single record in a file. While being preferred, the process of transforming a record key, to a corresponding main memory or external storage address, giving the bin or bucket location where the record can be found, is subject to certain disadvantages. Neither complete randomization nor a completely uniform distribution results when keys are converted to addresses by the usual random conversion transformations or hashing techniques. A transformation or hashing process is provided herein which not only leads to a greater degree of randomness than those heretofore known, but is so general that it is effective for both static and volatile files, and works well with all types, ranges, and lengths of keys. (Author)

Descriptors :   *Patent applications, *Data storage systems, *Addressing, Random access computer storage, Information retrieval, Files(Records), Computer architecture, Matching, Block oriented random access memories, Computer programs, Transformations, Computer logic, Boolean algebra, Algorithms, Flow charting, Tables(Data)

Subject Categories : Computer Programming and Software
      Computer Hardware

Distribution Statement : APPROVED FOR PUBLIC RELEASE