Instantiation of objects for information-sharing relationships

• US 20040034669A1
• Filed: 03/26/2003
• Published: 02/19/2004
• Est. Priority Date: 08/01/2002
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Smith, Wayne E., Liu, Jing, Stamos, James, Subramaniam, Mahesh
• Granted Patent: US 7,103,612 B2
• Time in Patent Office: Days
• US Class Current: 707/201
• CPC Class Codes: G06F 16/273 Asynchronous replication or reconciliation
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing

Abstract

A method and system are provided for instantiating objects for participation in information sharing relationships. According to one technique, a copy of an object is made, where the copy includes all changes made prior to a particular point in time, and no changes made after the particular point in time. The copy is used to create a second object. Data that reflects the particular point in time is stored, and subsequently used to determine which changes should be applied to the second object. Data that indicates that the creation time of the second object is stored, and subsequently used to determine which changes should be applied to the original object.

Claims

1. A method for instantiating objects that are to participate in an information sharing relationship, the method comprising the steps of:

making a copy of a first object that resides in a first system;

allowing changes to be made to said first object while said copy is being made;

wherein said first copy reflects all changes that were made permanent to said first object up to a particular point in time, and no changes that were made permanent to said first object after said particular point in time;

recording data that indicates said particular point in time;

creating a second object in a second system based on said copy of said first object;

causing data that indicates changes made in said first system to said first object to be sent to said second system;

wherein said data that indicates changes includes data that indicates a time at which said changes were made permanent in said first system; and

in said second system, determining whether to apply changes that were made to said first object to said second object based on a comparison between the time indicated for the changes and said particular point in time.

2. The method of claim 1 wherein the first system and the second system are the same system.

3. The method of claim 1 further comprising the step of registering said first object for instantiation, wherein the step of registering includes:

briefly locking the first object to ensure that there are no long-running transactions that hold modification locks on the first object; and

writing metadata to a metadata table in a source database in which the first object resides.

4. The method of claim 1 further comprising the step of storing in said second system a record that indicates said particular point in time.

5. The method of claim 1, wherein said second object is created at a second particular point in time, the method further comprising the steps of:

sending from said second system to said first system data that indicates said second particular point in time;

causing second data that indicates changes made in said second system to said second object to be sent to said first system;

wherein said second data includes data that indicates the time at which said changes were made permanent in said second system;

in said first system, determining whether to apply changes that were made to said second object to said first object based on a comparison between the time indicated for the changes and said second particular point in time.

6. The method of claim 1 wherein:

the step of making a copy of a first object that resides in a first system includes making a copy of a first database table that resides in a first database;

the step of allowing changes to be made to said first object while said copy is being made includes allowing changes to be made to said first database table while said copy is being made;

the step of creating a second object in a second system based on said copy of said first object includes creating a second database table in a second database;

the step of causing data that indicates changes made in said first system to said first object to be sent to said second system includes causing data that indicates changes made to said first table to be sent from a first database server that manages said first database to a second database server that manages the second database; and

the step of determining whether to apply changes includes the second database server performing a comparison between the time indicated for the changes and said particular point in time.

7. The method of claim 1 wherein:

the first system is a first database system;

the first object is a first database object;

the second system is a second database system; and

the step of making a copy is performed by exporting said first database object.

8. The method of claim 1 wherein:

the first system is a first database system;

the first object is a first database object;

the second system is a second database system; and

the steps of making a copy and creating said second object are performed by transporting a pluggable tablespace that contains said first database object from said first database system into said second database system.

9. The method of claim 1 wherein:

the first system is a first database system;

the first object is a first database object;

the second system is a second database system; and

the step of making a copy is performed using a recovery manager utility.

10. The method of claim 1 wherein:

the first system maintains a first logical clock to indicate a sequence to changes within the first system; and

the step of recording data that indicates said particular point in time includes recording said particular point in time relative to said first logical clock.

11. The method of claim 5 wherein:

the first system maintains a first logical clock to indicate a sequence to changes within the first system;

the step of recording data that indicates said particular point in time includes recording said particular point in time relative to said first logical clock;

the second system maintains a second logical clock to indicate a sequence to changes within said second system; and

the step of sending from said second system to said first system data that indicates said second particular point in time includes sending data that indicates said second particular point in time relative to said second logical clock.

12. The method of claim 5 wherein the step of sending from said second system to said first system data that indicates said second particular point in time includes:

prior to creating said second object, establishing an information sharing relationship between said first system and said second system;

based on said information sharing relationship, sending to the first system change records from said second system that reflect creation of the second object; and

the first system determining said second particular point in time based on said change records.

13. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 1.

14. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 2.

15. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 3.

16. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 4.

17. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 5.

18. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 6.

19. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 7.

20. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 8.

21. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 9.

22. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 10.

23. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 11.

24. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 12.