Browse Prior Art Database

Technique for Compare Files

IP.com Disclosure Number: IPCOM000088536D
Original Publication Date: 1977-Jun-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Hill, H: AUTHOR

Abstract

There is a frequent requirement to compare two files of the same logical record format to determine the differences between them. Such a requirement arises, for example, during audit inspection or when a delta file is required to update a program.

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Technique for Compare Files

There is a frequent requirement to compare two files of the same logical record format to determine the differences between them. Such a requirement arises, for example, during audit inspection or when a delta file is required to update a program.

The flow chart shows an efficient algorithm for file comparison which may be used on large or small files. The files are flow-charted as file X and file Y. Essentially the technique consists of using multiple pointers and comparing the values of those pointers to determine the minimum difference between files. Next, points are also compared with current points to decide Insert, Delete or Replace action. The technique is particularly useful for large files because the files do not require to be resident in main store.

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