Abstract: Full-text database systems require an in-dex to allow fast access to documents based on their content. We propose an inverted file indexing scheme based on compression. This scheme allows users to retrieve documents using words occurring in the doc-uments, sequences of adjacent words, and statistical ranking techniques. The compression methods cho-sen ensure that the storage requirements are small and that dynamic update is straightforward. The only as-sumption that we make is that sufficient main memory is available to support an in-memory vocabulary; given this assumption, the method we describe requires at most one disc access per query term to identify an-swers to queries.