Inverted Index Compression

Abstract

The data structure at the core of nowadays largescale search engines, social networks, and storage architectures is the inverted index. Given a collection of documents, consider for each distinct term t appearing in the collection the integer sequence `t , listing in sorted order all the identifiers of the documents (docIDs in the following) in which the term appears. The sequence `t is called the inverted list or posting list of the term t . The inverted index is the collection of all such lists. The scope of the entry is the one of surveying the most important encoding algorithms developed for efficient inverted index compression and fast retrieval.