United States Patent  [ii] Patent Number: 5,666,527
Tatsumi et al.  Date of Patent: Sep. 9, 1997
 SYSTEM FOR DYNAMICALLY CHANGING LOGICAL DATA STRUCTURE OF DATABASE
 Inventors: Tosbiharu Tatsumi; Hisayuki
Enbutsu. both of Kawasaki, Japan
 Assignee: Fujitsu Limited, Kawasaki, Japan
 Appl. No.: 644,121
 Filed: May 10,1996
Related U.S. Application Data
 Continuation of Ser. No. 128,147, Sep. 29,1993, abandoned.  Foreign Application Priority Data
Dec. 28, 1992 [JP] Japan 4-348404
 Int CI.6 G06F 17/30
 U.S. CI 395/612; 395/613
 Field of Search 395/611, 612,
 References Cited
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4,042,912 8/1977 Bachmanetal 395/600
5,307,486 4/1994 Nakamigawa 395/600
FOREIGN PATENT DOCUMENTS 2-066645 3/1990 Japan .
3- 067341 3/1991 Japan.
4- 139546 5/1992 Japan.
Suzuki et al, "A Database Control Function for Situations where Data may Increase Rapidly", Feb. 1981, pp. 1-15 Review of The Electrical Communication Laboratories vol. 29 No. 1-2.
Topper, 'The PC-JDMS Alliance", 1988, p. 104(15) PC
Tech. Journal, V6 N3.
Primary Examiner—Thomas G. Black
Assistant Examiner—Jack M. Choules
Attorney, Agent, or Firm—Staas & Halsey
A system for changing a logical data structure of a network type database in which an owner record is linked to member records by set-information identifying positions of the member records, the system includes a first unit for changing of a definition of a logical data structure of the network type database; and a second unit, when a member record to be linked to or linked to the owner record is added to or erased from the network type database in accordance with a changed logical data structure obtained by the first unit, for adding or erasing set-information of the added or erased member record to or from the set-pointer portion of the owner record, wherein an area of the set-pointer portion is changed in accordance with a variable-length management.
5 Claims, 16 Drawing Sheets