Top-k document retrieval in external memory

Abstract

Let D be a given set of (string) documents of total length n. The top-k document retrieval problem is to index D such that when a pattern P of length p, and a parameter k come as a query, the index returns those k documents which are most relevant to P. We present the first non-trivial external memory index supporting top-k document retrieval queries in optimal O(p/B+logB n+k/B) I/Os, where B is the block size. The index space is almost linear O(n log* n) words. © 2013 Springer-Verlag.