A comparison of algorithms for data base compression by use of fragments as language elements

The paper describes the advantages of using variable length equifrequent fragments as the language elements for compression coding of large data bases. The problem of finding the minimum space representation of the fragment compressed data base is equivalent to solving a shortest path problem. Three alternate algorithms for compression are described and their performance is tested on both word and text fragments. It is found that text fragments selected by a longest match algorithm produce the best results with regard to compression and use of processing time.