Computer-implemented method, computer program product and system for creating an index of a subset of data

摘要

A computer implemented method for transforming an inverted index of a collection of documents into a smaller inverted index of documents. The smaller index contains links to all and only to those documents appearing in a subset of the original collection of documents. The method avoids reprocessing the subset to create the smaller inverted index by intersecting each inverted list with the list of document references from the desired subset. If this intersection is empty then the list is removed from the new smaller index, otherwise the list containing only the intersected reference list is included in the new inverted index. The method is also extended to deal with creating multiple smaller inverted indexes and with propagating updates changes in the first collection of documents down into the smaller inverted index or indexes.