The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 27, 2012
Filed:
Nov. 07, 2007
Tomohiro Yasuda, Kokubunji, JP;
Makoto Iwayama, Tokorozawa, JP;
Osamu Imaichi, Koganei, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
To achieve high speed document search, an inverted index is compressed at high compressibility by an encoding method decodable in a high process speed. In compressing an identification number of a document to obtain a byte sequence by the variable byte method, w bits are used to represent the number of occurrences of the indexing term in the document, and x bits are used to represent additional information of the posting, where x and w are integers given as parameters. When the number of occurrences cannot be represented within w bits, a certain value indicating a numeric value that cannot be represented by w bits is stored is written to the said w bits, and anther byte sequence that represents the value by the variable byte method follows. Additionally provided is a means for reading a compressed posting from any position of a list of postings called inverted lists, allowing a binary search on an inverted list.