System and method for object persistence

• US 7,739,290 B2
• Filed: 12/17/2004
• Issued: 06/15/2010
• Est. Priority Date: 12/17/2004
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP (SAP SE)
• Inventors: Rossmann, Albert P.
• Primary Examiner(s): Pham; Khanh B
• Assistant Examiner(s): Yen; Syling
• Application Number:
  US11/015,102
• Publication Number:
  US 20060136464A1
• Time in Patent Office: 2,006 Days
• Field of Search: 707/4, 707/103.R, 707/103.X, 707/103.Y, 707/8, 707/9, 707/10, 707/101, 707/104.1, 707/203, 707/204, 709/223, 709/253, 717/102, 717/114, 717/116
• US Class Current: 707/755
• CPC Class Codes: G06F 16/289 Object oriented databases

Abstract

Embodiments of the invention are generally directed to a system and method for object persistence. In an embodiment, a proxy object is created based, at least in part, on object metadata stored in an internal data store of a persistence manager. The persistence manager may receive a request to access member data of a persistent object associated with the proxy object. In one embodiment, the persistence manager provides the member data from the proxy object.

Claims

1. A computer-implemented method for object persistence comprising:

generating a proxy class, by a persistent manager, based on metadata stored in a relational database;

receiving, by the persistence manager, a request via a proxy object of the proxy class to access member data of the relational database;

accessing the member data from the relational database;

storing, as object aggregates, the member data from the relational database as member data of a persistent object in an internal table of the persistent manager, wherein the object aggregates to enable loading of different parts of the persistent object instead of the entire persistent object;

organizing the member data in the internal table as belonging to a context for load, read, and write transaction;

selecting the member data based on the context of the member data;

directly accessing, by the persistent object, the member data stored in the internal table of the persistent manager, the directly accessed member data belonging to the selected context; and

providing the member data of the persistent object via the proxy object of the proxy class.

2. The method of claim 1, wherein generating the proxy class based on the metadata stored in the relational database comprises:

accessing from the relational database a database result set to obtain the object member data; and

creating the proxy object based, at least in part, on the metadata stored in the relational database, and wherein the directly accessed member data is associated with transactions that do not require deep copy of object hierarchies.

3. The method of claim 1, further comprising:

providing, by a transaction manager coupled with the persistent manger, a global unique identifier (GTTD), the transaction manger for managing consistency of transactions in the relational database; and

creating, by the persistent manager, an entry of a row set including the GTTD to provide capability to maintain nested transactions on the relational database.

4. The method of claim 2, further comprising:

reading the metadata from an attribute descriptor, wherein the attribute descriptor is to specify a data type and a name for each object attribute.

5. The method of claim 1, wherein providing the object member data from the proxy object comprises at least one of:

providing an object attribute from the proxy object; and

providing an object reference from the proxy object.

6. The method of claim 1, further comprising:

navigating the proxy object via a proxy object iterator.

7. The method of claim 1, further comprising:

reading, at a first server instance persistence manager, persistent object associated with metadata from the relational database; and

generating another proxy class and another proxy object based, at least in part, on the metadata stored in the relational database.

8. The method of claim 7, further comprising:

providing a transactional lock for at least a portion of the other proxy object from a central instance transaction manager to a first service instance transaction manager.

9. The method of claim 8, further comprising:

providing a transactional lock for at least a portion of the other proxy object from the first server instance transaction manager to a second server instance transaction manager.

10. The method of claim 7, further comprising:

creating a fixed size memory block for the internal data store of a central instance persistence manager; and

creating a fixed size memory block for an internal data store of the first server instance persistence manager.

11. The method of claim 1, wherein the accessing based on a database view of the relational database, and wherein the database view is configured for extracting member data from one or more relational databases.

12. The method of claim 1, wherein the context aggregates the member data in sets of the load, read, and write transactions for executing a commit or a rollback.

13. The method of claim 1, further comprising:

redirecting to the internal table the request to access the member data.

14. The method of claim 1, further comprising:

determining access rights of the member data via an attribute descriptor in the internal table, the attribute descriptor specifying a programming language name, type of member data, and public and private scope of the access rights; and

selecting the member data based on the access rights.

15. The method of claim 1, further comprising:

executing a commit or a rollback on the persistent object when the transaction is complete.

16. An apparatus comprising:

an application to request member data of a persistent object; and

a processor and a logic executable thereon to perform the method including;

generating a proxy class, by a persistent manager, based on metadata stored in a relational database;

receiving, by the persistence manager, a request via a proxy object of the proxy class to access member data of the relational database;

accessing the member data from the relational database;

storing, as object aggregates, the member data from the relational database as member data of a persistent object in an internal table of the persistent manager, wherein the object aggregates to enable loading of different parts of the persistent object instead of the entire persistent object;

organizing the member data in the internal table as belonging to a context for load, read, and write transaction;

selecting the member data based on the context of the member data;

directly accessing, by the persistent object, the member data stored in the internal table of the persistent manager, the directly accessed member data belonging to the selected context; and

providing the member data of the persistent object via the proxy object of the proxy class.

17. The apparatus of claim 16, wherein the logic executable thereon to generate the proxy object based, at least in part, on object metadata stored in the relational database comprises logic to perform the method comprising:

accessing from the relational database a database result set to obtain the metadata; and

creating the proxy object based, at least in part, on the metadata obtained from the database result set, and wherein the directly accessed member data is associated with transactions that do not require deep copy of object hierarchies.

18. The apparatus of claim 16, wherein the processor and the logic to further to perform the method including:

providing, by a transaction manager coupled with the persistent manger, a global unique identifier (GTTD), the transaction manger for managing consistency of transactions in the relational database; and

creating, by the persistent manager, an entry of a row set including the GTTD to provide capability to maintain nested transactions on the relational database.

19. The apparatus of claim 17, wherein the database result set is based, at least in part, on a database view.

20. The apparatus of claim 17, wherein the logic executable thereon further comprises logic to:

reading the metadata from an attribute descriptor, wherein the attribute descriptor is to specify a data type and a name for each object attribute.

21. The apparatus of claim 16, wherein the accessing based on a database view of the relational database, and wherein the database view is configured for extracting member data from one or more relational databases.

22. The apparatus of claim 16, wherein the context aggregates the member data in sets of the load, read, and write transactions for executing a commit or a rollback.

23. The apparatus of claim 16, wherein the processor and the logic to further to perform the method including:

redirecting to the internal table the request to access the member data.

24. The apparatus of claim 16, wherein the processor and the logic to further to perform the method including:

determining access rights of the member data via an attribute descriptor in the internal table, the attribute descriptor specifying a programming language name, type of member data, and public and private scope of the access rights; and

selecting the member data based on the access rights.

25. The apparatus of claim 16, wherein the processor and the logic to further to perform the method including:

executing a commit or a rollback on the persistent object when the transaction is complete.

26. An article of manufacture comprising:

a computer-readable medium having content stored thereon to provide instructions that, when executed, result in an electronic device to perform operations including;

generating a proxy class, by a persistent manager, based on metadata stored in a relational database;

receiving, by the persistence manager, a request via a proxy object of the proxy class to access member data of the relational database;

accessing the member data from the relational database;

storing, as object aggregates, the member data from the relational database as member data of a persistent object in an internal table of the persistent manager, wherein the object aggregates to enable loading of different parts of the persistent object instead of the entire persistent object;

organizing the member data in the internal table as belonging to a context for load, read, and write transaction;

selecting the member data based on the context of the member data;

directly accessing, by the persistent object, the member data stored in the internal table of the persistent manager, the directly accessed member data belonging to the selected context; and

providing the member data of the persistent object via the proxy object of the proxy class.

27. The article of manufacture of claim 26, further comprising instructions that, when executed, result in the electronic device to perform further operations including:

accessing from the relational database a database result set to obtain the object metadata; and

creating the proxy class and proxy object based on the metadata stored in the relational database, and wherein the directly accessed member data is associated with transactions that do not require deep copy of object hierarchies.

28. The article of manufacture of claim 26, further comprising instructions that, when executed, result in the electronic device to perform further operations including:

providing, by a transaction manager coupled with the persistent manger, a global unique identifier (GTTD), the transaction manger for managing consistency of transactions in the relational database; and

creating, by the persistent manager, an entry of a row set including the GTTD to provide capability to maintain nested transactions on the relational database.

29. The article of manufacture of claim 27, wherein the database result set is based, at least in part, on a database view.

30. The article of manufacture of claim 26, wherein the accessing based on a database view of the relational database, and wherein the database view is configured for extracting member data from one or more relational databases.

31. The article of manufacture of claim 26, wherein the context aggregates the member data in sets of the load, read, and write transactions for executing a commit or a rollback.

32. The article of manufacture of claim 26, further comprising instructions that, when executed, result in the electronic device to perform further operations including:

redirecting to the internal table the request to access the member data.

33. The article of manufacture of claim 26, further comprising instructions that, when executed, result in the electronic device to perform further operations including:

determining access rights of the member data via an attribute descriptor in the internal table, the attribute descriptor specifying a programming language name, type of member data, and public and private scope of the access rights; and

selecting the member data based on the access rights.

34. The article of manufacture of claim 26, further comprising instructions that, when executed, result in the electronic device to perform further operations including:

executing a commit or a rollback on the persistent object when the transaction is complete.