Method and apparatus for managing metadata in a database management system

• US 6,535,868 B1
• Filed: 08/27/1998
• Issued: 03/18/2003
• Est. Priority Date: 08/27/1998
• Status: Expired due to Term

• Current Assignee: Teradata US, Inc. (Teradata Corporation)
• Original Assignee: NCR Corporation (NCR Voyix Corporation)
• Inventors: Galeazzi, Debra A., Mower, Kristen Roi, McLean, Bruce A., Stellwagen, Richard G. Jr.
• Primary Examiner(s): Alam, Hosain T.
• Application Number:
  US09/141,239
• Time in Patent Office: 1,664 Days
• Field of Search: 707/8, 707/1-2, 707/10, 707/200-202, 707/100
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2343 Locking methods, e.g. distributed locking or locking implementation details
• CPC Class Codes: G06F 16/2365 Ensuring data consistency and integrity
• CPC Class Codes: G06F 16/25 Integrating or interfacing systems involving database management systems
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing

Abstract

A method, apparatus, and article of manufacture for managing metadata in a database management system is disclosed. The method comprises the steps of accepting a command in the database management system that implicates a metadata modification and providing that command to a metadata service, parsing the command to determine if the command requires a metadata modification, accessing a rule set defining rules for modifying the metadata when indicated by the parsed commands, and enforcing the rule defined in the rule set. The article of manufacture comprises a program storage device with a medium tangibly embodying processing instructions for performing the foregoing operations. The apparatus comprises a means for performing the foregoing steps. The article of manufacture comprises a means for performing these steps, including a computer implementing a database management system. The functions herein described can be performed by a special purpose processor, a single multipurpose computer. Alternatively, the operations disclosed herein can be performed among a number of computers communicatively interconnected by a network such as a local area network, wide area network, or the Internet.

Claims

1. A method of managing metadata in a database management system, comprising the steps of:

accepting a command in the database management system from a system component, wherein execution of the command implicates a metadata modification;

transmitting the command to a metadata service;

parsing the command to determine if the command requires a metadata modification;

accessing a rule set defining rules for modifying the metadata when the command requires a metadata modification, wherein the rule set includes a rule requiring negotiation of the metadata modification between the system component and a second system component accessing the database management system; and

enforcing the rule defined in the rule set.

2. The method of claim 1, wherein the metadata modification is categorized into a metadata modification type and the rule comprises the metadata modification type.

3. The method of claim 1, wherein the rule set comprises predicate rules which are enforced before the metadata change is prepared and subsequent rules which are enforced after the metadata change is committed.

4. The method of claim 1, wherein the rule set comprises a notify rule to notify a second system component of the metadata modification and to allow the metadata modification if the second system component approves.

5. The method of claim 1, wherein the rule set comprises an alert rule to alert a second system component of the metadata modification.

6. The method of claim 1, wherein the rule set comprises a block rule to block the metadata modification.

7. The method of claim 1, further comprising the steps of:

accepting a suspend request associated with a rule in the metadata service;

suspending the rule specified by the suspend request; and

notifying a second system component of the suspended rule.

8. The method of claim 1, further comprising the step of transmitting an outcome of the command from the database management system.

9. The method of claim 1, wherein the database command affects the database management system schema.

10. The method of claim 1, wherein the command is transmitted to the metadata service via a replication service.

11. The method of claim 1, wherein the command is described by a database definition language.

12. The method of claim 1, wherein the rule set is stored as a table in the database management system.

13. The method of claim 1, wherein the command transmitted to the metadata services is a prepare command transmitted via a request coordinator in the relational database management system, and the step of enforcing the rule defined in the rule set comprises the steps of:

transmitting a prepare acknowledgement message from the metadata service, receiving a commit message in the metadata service, and transmitting a commit acknowledgement message from the metadata service when the rule allows the metadata modification; and

transmitting an abort message from the metadata service and receiving an abort message in the metadata service when the rule does not allow the metadata modification.

14. An apparatus for managing metadata in a database management system, comprising:

means for receiving a command from a system component in a metadata service, wherein execution of the command implicates a metadata modification;

means for parsing the command to determine if the command requires a metadata modification;

means for accessing a rule set defining rules for modifying the metadata when the command requires a metadata modification, wherein the rule set includes a rule requiring negotiation of the metadata modification between the system component and a second system component accessing the database management system; and

means for enforcing the rule defined in the rule set.

15. The apparatus of claim 14, wherein the metadata modification is categorized into a metadata modification type and the rule comprises the metadata modification type.

16. The apparatus of claim 14, wherein the rule set comprises predicate rules which are enforced before the metadata change is prepared and subsequent rules which are enforced after the metadata change is committed.

17. The apparatus of claim 14, wherein the rule set comprises a notify rule to notify a second system component of the metadata modification and to allow the metadata modification if the second system component approves.

18. The apparatus of claim 14, wherein the rule set comprises an alert rule to alert a second system component of the metadata modification.

19. The apparatus of claim 14, wherein the rule set comprises a block rule to bock the metadata modification.

20. The apparatus of claim 14, further comprising:

means for accepting a suspend request associated with a rule in the metadata service;

means for suspending the rule specified by the suspend request; and

means for notifying a second system component of the suspended rule.

21. The apparatus of claim 14, further comprising means for transmitting an outcome of the command from the database management system.

22. The apparatus of claim 14, wherein the database command affects the database management system schema.

23. The apparatus of claim 14, wherein the command is transmitted to the metadata service via a replication service.

24. The apparatus of claim 14, wherein the command is described by a database definition language.

25. The apparatus of claim 14, wherein the rule set is stored as a table in the database management system.

26. The apparatus of claim 14, wherein the command transmitted to the metadata services is a prepare command transmitted via a request coordinator in the relational database management system, and the step of enforcing the rule defined in the rule set comprises the steps of:

transmitting a prepare acknowledgement message from the metadata service, receiving a commit message in the metadata service, and transmitting a commit acknowledgement message from the metadata service when the rule Allows the metadata modification; and

transmitting an abort message from the metadata service and receiving an abort message in the metadata service when the rule does not allow the metadata modification.

27. A program storage device, readable by computer having a processor and a memory, tangibly embodying one or more programs of instructions executable by the computer to perform the method steps of managing metadata in a database management system, the method steps comprising the steps of:

accepting a command in the database management system from a system component, wherein execution of the command implicates a metadata modification;

transmitting the command to a metadata service;

parsing the command to determine if the command requires a metadata modification;

accessing a rule set defining rules for modifying the metadata when the command requires a metadata modification, wherein the rule set includes a rule requiring negotiation of the metadata modification between the system component and a second system component accessing the database management system; and

enforcing the rule defined in the rule set.

28. The program storage device of claim 27, wherein the metadata modification is categorized into a metadata modification type and the rule comprises the metadata modification type.

29. The program storage device of claim 27, wherein the rule set comprises predicate rules which are enforced before the metadata change is prepared and subsequent rules which are enforced after the metadata change is committed.

30. The program storage device of claim 27, wherein the rule set comprises a notify rule to notify a second system component of the metadata modification and to allow the metadata modification if the second system component approves.

31. The program storage device of claim 27, wherein the rule set comprises an alert rule to alert a second system component of the metadata modification.

32. The program storage device of claim 27, wherein the rule set comprises a block rule to bock the metadata modification.

33. The program storage device of claim 27, wherein the method steps further comprise the steps of:

accepting a suspend request associated with a rule in the metadata service;

suspending the rule specified by the suspend request; and

notifying a second system component of the suspended rule.

34. The program storage device of claim 27, wherein the method steps further comprise the step of transmitting an outcome of the command from the database management system.

35. The program storage device of claim 27, wherein the database command affects the database management system schema.

36. The program storage device of claim 27, wherein the command is transmitted to the metadata service via a replication service.

37. The program storage device of claim 27, wherein the command is described by a database definition language.

38. The program storage device of claim 27, wherein the rule set is stored as a table in the database management system.

39. The program storage device of claim 27, wherein the command transmitted to the metadata services is a prepare command transmitted via a request coordinator in the relational database management system, and the method step of enforcing the rule defined in the rule set comprises the method steps of:

transmitting a prepare acknowledgement message from the metadata service, receiving a commit message in the metadata service, and transmitting a commit acknowledgement message from the metadata service when the rule allows the metadata modification; and

transmitting an abort message from the metadata service and receiving an abort message in the metadata service when the rule does not allow the metadata modification.