Reference Work Entry

Encyclopedia of Database Systems

pp 1571-1574

Inverted Files

  • Edleno Silva de MouraAffiliated withFederal University of Amazonas
  • , Marco Antonio CristoAffiliated withFUCAPI


Inverted index; Full text inverted index; Postings file


An Inverted file is an index data structure that maps content to its location within a database file, in a document or in a set of documents. It is normally composed of: (i) a vocabulary that contains all the distinct words found in a text and (ii), for each word t of the vocabulary, a list that contains statistics about the occurrences of t in the text. Such list is known as the inverted list of t. The inverted file is the most popular data structure used in document retrieval systems to support full text search.

Historical Background

Efforts for indexing electronic texts are found in literature since the beginning of the computational systems. For example, descriptions of Electronic Information Search Systems that are able to index and search text can be found in the early 1950s [4].

In a seminal work, Gerard Salton wrote a book in 1968, containing the basis for the modern inf ...

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