Method and system for maintaining persistence in a shared object system

• US 6,032,153 A
• Filed: 01/30/1998
• Issued: 02/29/2000
• Est. Priority Date: 11/13/1997
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Electronic Data Systems Corporation (Perspecta, Inc.)
• Inventors: Swift, William Earl II, Marney, Steven H., Sadiq, Waqar, Cummins, Fred Arthur
• Primary Examiner(s): Lintz, Paul R.
• Assistant Examiner(s): FLEURANTIN, JEAN B
• Application Number:
  US09/016,077
• Time in Patent Office: 760 Days
• Field of Search: 707/103, 707/104, 707/8
• US Class Current: 1/1
• CPC Class Codes: G06F 16/289 Object oriented databases
• CPC Class Codes: G06F 9/524 Deadlock detection or avoidance
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing

Abstract

One aspect of the invention is a method for maintaining persistence in a shared object system. A request is received to update a persistent record of a shared object'"'"'s state wherein the persistent record of the shared object'"'"'s state is contained in a database. At least one SQL statement is dynamically generated in response to the request. That statement is generated using a data structure comprising data reflecting at least a portion of the state of the shared object and a map associating attributes to the shared object with the location of those attributes in the database. An SQL statement is then sent to the database.

Claims

1. A method for maintaining persistence in a shared object system, comprising:

receiving a request to update a persistent record of a shared object'"'"'s state wherein the persistent record of the shared object'"'"'s state is contained in a database;

dynamically generating at least one SQL statement in response to the request, the SQL statement generated using a data structure comprising data reflecting at least a portion of the state of the shared object and a map comprising a plurality of entries, each entry associating an attribute of the shared object with the location of that attribute in the database; and

sending the SQL statement to the database.

2. The method of claim 1, wherein the sending of the SQL statement causes at least one change in the persistent record of the shared object'"'"'s state.

3. The method of claim 1, wherein the map comprises a list of records, each record associated with an attribute of the shared object and comprising the attribute name, database column name, data type, database table name, and key type.

4. The method of claim 3, wherein each record further comprises a system assigned key indicator.

5. The method of claim 1, wherein the data structure comprises a plurality of name/value pairs, each name/value pair comprising an attribute name and the current value of the attribute having that attribute name in the shared object.

6. The method of claim 1, wherein the data structure comprises attributes that have been changed wherein those changes are not reflected in the database.

7. The method of claim 6, wherein the data structure further comprises object identifiers comprising identifiers of objects related to the shared object.

8. The method of claim 6, wherein a dirty indicator is associated with each attribute of the shared object, the dirty indicators used to create the data structure, and wherein an attribute'"'"'s dirty indicator is set to indicate dirty when the attribute is changed and set to indicate not dirty when the database is updated to reflect a change in the attribute.

9. The method of claim 1, wherein the data structure comprises each attribute of the shared object that is persistently maintained by the database.

10. The method of claim 5, wherein the map comprises a list of records, each record associated with an attribute of the shared object and comprising the attribute name, database column name, data type, database table name, and key type.

11. The method of claim 10, wherein the data structure comprises attributes that have been changed wherein those changes are not reflected in the database.

12. A shared object system, comprising:

a data structure comprising data reflecting at least a portion of the state of a shared object;

a map comprising a plurality of entries, each entry associating an attribute of the shared object with the location of that attribute in a database; and

an update method operable to receive a request to update a persistent record of a shared object'"'"'s state wherein the persistent record of the shared object'"'"'s state is contained in the database, dynamically generate at least one SQL statement in response to the request, the SQL statement generated by using the data structure and the map, and

send the SQL statement to the database.

13. The shared object system of claim 12, wherein the map comprises a list of records, each record associated with an attribute of the shared object and comprising the attribute name, database column name, data type, database table name, and key type.

14. The shared object system of claim 12, wherein the data structure comprises a plurality of name/value pairs, each name/value pair comprising an attribute name and the current value of the attribute having that attribute name in the shared object.

15. The shared object system of claim 12, wherein the data structure comprises attributes that have been changed wherein those changes are not reflected in the database.

16. The shared object system of claim 12, further comprising:

a dirty indicator associated with each attribute of the shared object, the dirty indicators used to create the data structure, and wherein an attribute'"'"'s dirty indicator is set to indicate dirty when the attribute is changed and set to indicate not dirty when the database is updated to reflect a change in the attribute.

17. The shared object system of claim 16, wherein the data structure is created in response to a transaction and wherein an attribute is placed in the data structure during such creation if its dirty indicator is set to indicate dirty.

18. The shared object system of claim 17, wherein the data structure at least one object identifier is placed in the data structure during creation of the data structure, the object identifier representing an object related to the shared object.

19. The shared object system of claim 12, wherein the data structure comprises each attribute of the shared object that is persistently maintained by the database.

20. The shared object system of claim 16, wherein the map comprises a list of records, each record associated with an attribute of the shared object and comprising the attribute name, database column name, data type, database table name, and key type.