Hashing and trie algorithms for partial match retrieval

Abstract

File designs suitable for retrieval from a file of k -letter words when queries may be only partially specified are examined. A new class of partial match file designs (called PMF designs) based upon hash coding and trie search algorithms which provide good worst-case performance is introduced. Upper bounds on the worst-case performance of these designs are given along with examples of files achieving the bound. Other instances of PMF designs are known to have better worst-case performances. The implementation of the file designs with associated retrieval algorithms is considered. The amount of storage required is essentially that required of the records themselves.