Inverted Files

Inverted Files When I refer to an " index for a text collection " , I usually mean " inverted file ". An inverted file for a collection C realizes a mapping from each term appearing in C to all its occurrences. Each term is associated with an inverted list (aka posting list). The level of granularity might be documents (in which case a term's posting list is a list of all documents in which the term appears) or a list of exact word positions. The elements of the posting list are usually simple integers.