公开(公告)号：CA1191616A

公开(公告)日：1985-08-06

申请号：CA426778

申请日：1983-04-27

Applicant: IBM

Inventor： HADERLE DONALD J ,  SHAN MING-CHIEN ,  PUTZOLU GIANFRANCO R ,  TRAIGER IRVING L

IPC: G06F12/00 ,  G06F7/22 ,  G06F9/06 ,  G06F9/30 ,  G06F13/00 ,  G06F17/30

Abstract: METHOD AND APPARATUS FOR ONLINE DEFINITION OF DATABASE DESCRIPTORS A computing system is characterized by a database management system which provides method and apparatus for online definition of data descriptors while maintaining the availability of data and data descriptors not impacted by a concurrent definitional process. Under the control of the database management system of the invention, the domain effected by the definitional process is determined, transactions which reference descriptors within the domain effected by the definitional process are marked for rebinding, prior-to-commit access by transactions which have not been prebound to objects within the domain effected by the definitional process is inhibited, and thereafter all accesses to objects in the domain are allowed.

公开(公告)号：CA1325681C

公开(公告)日：1993-12-28

申请号：CA607387

申请日：1989-08-02

Applicant: IBM

Inventor： CRUS RICHARD A ,  DOCKTER MICHAEL J ,  ENGLES ROBERT W ,  HADERLE DONALD J

IPC: G06F12/00 ,  G06F7/00 ,  G06F17/30 ,  G06F15/40

Abstract: An implementation of referential integrity in which descriptions of referential constraints are compiled into meta-data descriptions of the constraint rules and specifications. The meta-data descriptions of the constraints are stored in the form of objects called relationship descriptors. Each relationship descriptor contains a complete description of a referential constraint, either directly or by means of pointers to other objects such a record and index descriptors which contain information comprised in the constraint's specification. The relationship descriptors are linked into two types of chains by symbolic pointers. One type of relationship descriptor chain connects all relationship descriptors which have a common parent table. The other type of relationship descriptor chain connects relationship descriptors with common dependent tables. Both types of chains are anchored in respective fields in the tables' record descriptors. The use of meta-data descriptors facilitates both ready modification of the constraints, and speedy enforcement of the constraints by a single, shared procedure which may be embedded in the data base manager.

公开(公告)号：AU617846B2

公开(公告)日：1991-12-05

申请号：AU3953689

申请日：1989-08-11

Applicant: IBM

Inventor： CRUS RICHARD A ,  DOCKTER MICHAEL J ,  ENGLES ROBERT W ,  HADERLE DONALD J

IPC: G06F12/00 ,  G06F7/00 ,  G06F17/30 ,  G06F15/20 ,  G06F15/40

Abstract: An implementation of referential integrity in which descriptions of referential constraints are compiled into meta-data descriptions of the constraint rules and specifications. The meta-data descriptions of the constraints are stored in the form of objects called relationship descriptors. Each relationship descriptor contains a complete description of a referential constraint, either directly or by means of pointers to other objects such as record and index descriptors which contain information comprised in the constraint's specification. The relationship descriptors are linked into two types of chains by symbolic pointers. One type of relationship descriptor chain connects all relationship descriptors which have a common parent table. The other type of relationship descriptor chain connects relationship descriptors with common dependent tables. Both types of chains are anchored in respective fields in the tables' record descriptors. The use of meta-data descriptors facilitates both ready modification of the constraints, and speedy enforcement of the constraints by a single, shared procedure which may be embedded in the data base manager.