(12) United States Patent ao) Patent No.: us 6,189,006 Bi
Fukushima (45) Date of Patent: *Feb. 13,2001
(54) FULL-TEXT INDEX PRODUCING DEVICE FOR PRODUCING A FULL-TEXT INDEX AND FULL-TEXT DATA BASE RETRIEVING DEVICE HAVING THE FULL-TEXT INDEX
(75) Inventor: Toshikazu Fukushima, Tokyo (JP)
(73) Assignee: NEC Corporation, Tokyo (JP)
( * ) Notice: Under 35 U.S.C. 154(b), the term of this patent shall be extended for 0 days.
This patent is subject to a terminal disclaimer.
(21) Appl. No.: 09/260,535
(22) Filed: Mar. 2, 1999
Related U.S. Application Data
(63) Continuation of application No. 08/845,038, filed on Apr. 21, 1997, now Pat. No. 5,940,836.
(30) Foreign Application Priority Data
Apr. 19, 1996 (JP) 8-098050
(51) Int. C I. G06F 17/30
(52) U.S. CI 707/6; 707/104; 382/177
(58) Field of Search 709/227, 204;
707/104, 201, 6, 102, 103; 705/26; 455/414, 461; 395/101; 382/177, 311
(56) References Cited
U.S. PATENT DOCUMENTS
4,985,863 1/1991 Fujisawa et al 364/900
5,265,242 11/1993 Fujisawa et al 395/600
5,309,359 * 5/1994 Katz et al 707/102
5,404,295 * 4/1995 Katz et al 707/2
5,544,049 * 8/1996 Henderson et al 704/7
5,724,457 * 3/1998 Fukushima 382/311
5,724,571 * 3/1998 Woods 707/5
5,734,749 * 3/1998 Yamada et al 382/187
5,745,899 * 4/1998 Burrows 707/102
5.748.953 * 5/1998 Mizutani et al 707/6
5.748.954 * 5/1998 Mauldin 707/10
5,784,608 * 7/1998 Meske, Jr. et al 707/2
5,826,261 * 10/1998 Spencer 707/5
5,864,855 * 1/1999 Ruocco et al 707/10
5,864,871 * 1/1999 Kitain et al 707/104
5,878,423 * 3/1999 Anderson et al 707/100
5,915,249 * 6/1999 Spencer 707/5
5,920,859 * 7/1999 Li 707/5
5,930,805 * 7/1999 Marquis 707/201
5,940,836 * 8/1999 Fukushima 707/104
6,014,460 * 1/2000 Fukushima et al 382/177
* cited by examiner
Primary Examiner—-Thomas G. Black
Assistant Examiner—Charles L. Rones
(74) Attorney, Agent, or Firm—Sughrue, Mion, Zinn,
Macpeak & Seas, PLLC
(57) ABSTRACT
A full-text data base retrieving device retrieves a data base in accordance with a query. A full-text index has character location information representative of location of each of key character sequences of N characters that appear in the data base, where N is a positive integer. A query memory memorizes the query as a retrieval key character sequence. A separating section separates the retrieval key character sequence into a plurality of retrieval key character sequences of N characters to extract contexts as extracted contexts from the retrieval key character sequence in accordance with the retrieval key character sequences. A context classifying section classifies the extracted contexts into classified contexts having the classification numbers, respectively. An index retrieving section retrieves the full-text index in accordance with the sorts of the retrieval key character sequences and the classified contexts to read the character location information as a retrieval result out of the full-text index. A detecting section detects appearance locations of the retrieval key character sequence in the full-text data base to produce the appearance locations as a detected result.
6 Claims, 7 Drawing Sheets
