System for dynamically changing logical data structure of database

[54] SYSTEM FOR DYNAMICALLY CHANGING LOGICAL DATA STRUCTURE OF DATABASE

[75] Inventors: Tosbiharu Tatsumi; Hisayuki

Enbutsu. both of Kawasaki, Japan

[73] Assignee: Fujitsu Limited, Kawasaki, Japan

[21] Appl. No.: 644,121

[22] Filed: May 10,1996

Related U.S. Application Data

[63] Continuation of Ser. No. 128,147, Sep. 29,1993, abandoned. [30] Foreign Application Priority Data

Dec. 28, 1992 [JP] Japan 4-348404

[51] Int CI.6 G06F 17/30

[52] U.S. CI 395/612; 395/613

[58] Field of Search 395/611, 612,

395/613

[56] References Cited

U.S. PATENT DOCUMENTS

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.

OTHER PUBLICATIONS

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

[57] ABSTRACT

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