Nearest-neighbour Searching in Files of Text Signatures Using Transputer Networks

This paper discusses the implementation of nearest-neighbour document retrieval in serial files using transputer networks. The system uses a two-stage retrieval algorithm in which an initial text-signature search is used to exclude large numbers of documents from the detailed and time-consuming pattern-matching search. The latter is implemented using a processor farm, so that documents which match at the signature level can be examined in parallel to determine whether they are, in fact, a good match for the query. The results demonstrate that communication is the critical factor in all of the transputer networks that were investigated. A high degree of speed-up can be obtained when only the pattern-matching search is carried out. When text signatures are used, however, the speed-up is less, decreasing in line with an increase in the size of the text signatures that are used.