Patent ID: 8549000

Claim:
A data processing system comprising: memory storing an inverted index comprising a plurality of entries, wherein i) a first of the entries includes a plurality of document identifiers each identifying a document, ii) a second of the entries identifies at least one word, concept, or image and includes a pointer to the first of the entries, and iii) a third of the entries identifies at least one word, concept, or image that differs from the at least one word, concept, or image identified by the second of the entries and includes a pointer to the first of the entries, wherein the first entry is a combined entry related to the second of the entries and the third of the entries; and one or more data processors programmed to retrieve document identifiers that identify documents responsive to search queries, the retrieving including receiving a first search query to which the at least one word, concept, or image identified by the second of the entries is responsive, locating the second of the entries in the inverted index using the first search query, following the pointer in the second of the entries to the first of the entries, retrieving at least some of the plurality of document identifiers in the first of the entries for responding to the first search query, receiving a second search query to which the at least one word, concept, or image identified by the third the entries is responsive, locating the third of the entries in the inverted index using the second search query, following the pointer in the third of the entries to the first of the entries, and retrieving at least some of the plurality of document identifiers in the first of the entries for responding to the second search query.