Method and mechanism for batch processing transaction logging records

• US 6,976,022 B2
• Filed: 09/16/2002
• Issued: 12/13/2005
• Est. Priority Date: 09/16/2002
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Vemuri, Srinivas, Ganesh, Amit, Klein, Jonathan, Joshi, Vikram, Nithrakashyap, Arvind, Bamford, Roger
• Primary Examiner(s): Mizrahi, Diane D.
• Application Number:
  US10/245,118
• Publication Number:
  US 20040054643A1
• Time in Patent Office: 1,184 Days
• Field of Search: 707/200, 707/201, 707/202, 707/203, 707/204, 707/205, 707/206, 707/1, 707/8
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2358 Change logging, detection, and notification replication G06F16/27
• CPC Class Codes: G06F 16/2365 Ensuring data consistency and integrity
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database

Abstract

A method and mechanism is disclosed for implementing transaction logging in a database system. In-memory undo records are maintained to log undo information for the database system. Redo records are batch processed, with multiple redo records for a transaction stored on disk at commit time.

Claims

1. A method for implementing redo records in a database system, comprising:

receiving a request to process a first transaction, the first transaction comprising one or more updates to a database;

forming a set of redo information corresponding to the one or more updates to the database by the first transaction, the set of redo information comprising one or more redo information items;

generating the set of redo information in memory, wherein the one or more redo information items are not individually persisted; and

upon a commit of the first transaction, batch persisting the set of redo information as a group.

2. The method of claim 1 in which the memory comprises shared memory.

3. The method of claim 2 in which the set of redo information is stored in a private region of the shared memory.

4. The method of claim 1 in which the one or more redo information items are created in a final format instead of an intermediate format.

5. The method of claim 1 in which the set of data acted upon by the first transaction is exclusively locked.

6. The method of claim 5 in which second transaction acts upon the set of data updated by the first transaction.

7. The method of claim 6 in which selected ones of the one or more redo information items for which dependency exists for the second transaction are removed from batch processing.

8. The method of claim 6 in which all of the one or more redo information items are removed from batch processing.

9. The method of claim 6 in which the first transaction is downgraded such that it no longer continue batch processing redo information.

10. The method of claim 6 in which the first transaction continues to batch process redo information.

11. The method of claim 1 in which the set of redo information is optimized before being persisted.

12. The method of claim 11 in which the set of redo information is optimized by collapsing redo information items to remove intermediate changes to data items.

13. The method of claim 1 in which the set of redo information is batch persisted by writing to a redo log on disk.

14. The method of claim 1 in which the set of one or more redo information items is persisted as a single redo record.

15. The method of claim 1 in which undo information is not persisted.

16. The method of claim 1 in which the act of processing an update to the database is separated from the act of generating redo information.

17. The method of claim 1 in which the one or more updates are not persisted until the set of redo information is persisted.

18. A computer program product comprising a computer usable medium having executable code to execute a process for implementing redo records in a database system, the process comprising:

receiving a request to process a first transaction, the first transaction comprising one or more updates to a database;

forming a set of redo information corresponding to the one or more updates to the database by the first transaction, the set of redo information comprising one or more redo information items;

generating the set of redo information in memory, wherein the one or more redo information items are not individually persisted; and

upon a commit of the first transaction, batch persisting the set of redo information as a group.

19. The computer program product of claim 18 in which the memory comprises shared memory.

20. The computer program product of claim 19 in which the set of redo information is stored in a private region of the shared memory.

21. The computer program product of claim 18 in which the one or more redo information items are created in a final format instead of an intermediate format.

22. The computer program product of claim 18 in which the set of data acted upon by the first transaction is exclusively locked.

23. The computer program product of claim 22 in which second transaction acts upon the set of data updated by the first transaction.

24. The computer program product of claim 23 in which selected ones of the one or more redo information items for which dependency exists for the second transaction are removed from batch processing.

25. The computer program product of claim 23 in which all of the one or more redo information items are removed from batch processing.

26. The computer program product of claim 23 in which the first transactioin is downgraded such that it no longer continue batch processing redo information.

27. The computer program product of claim 23 in which the first transaction continues to batch process redo information.

28. The computer program product of claim 18 in which the set of redo information is optimized before being persisted.

29. The computer program product of claim 28 in which the set of redo information is optimized by collapsing redo information items to remove intermediate changes to data items.

30. The computer program product of claim 18 in which the set of redo information is batch persisted by writing to a redo log on disk.

31. The computer program product of claim 18 which the set of one or more redo information items is persisted as a single redo record.

32. The computer program product of claim 18 in which undo information is not persisted.

33. The computer program product of claim 18 in which the act of processing an update to the database is separated from the act of generating redo information.

34. The computer program product of claim 18 in which the one or more updates are not persisted until the set of redo information is persisted.

35. A system for implementing redo records in a database system, comprising:

means for receiving a request to process a first transaction, the first transaction comprising one or more updates to a database;

means for forming a set of redo information corresponding to the one or more updates to the database by the first transaction, the set of redo information comprising one or more redo information items;

means for generating the set of redo records in memory, wherein the one or more redo records are not individually persisted; and

means for impolementing, upon a commit of the first transaction, batch persisting the set of redo information as a group.

36. The system of claim 35 in which the memory comprises shared memory.

37. The system of claim 36 in which the set of redo information is stored in a privated region of the shared memory.

38. The system of claim 35 in which the one or more redo information items are created in a final format instead of an intermediate format.

39. The system of claim 35 in which the set of data acted upon by the first transaction is exclusively locked.

40. The system of claim 39 in which second transaction acts upon the set data updated by the first transaction.

41. The system of claim 40 in which selected ones of the one or more redo information items for which dependency exists for the second transaction are removed from batch processing.

42. The system of claim 40 in which all of the one or more redo information items are removed from batch processing.

43. The system of claim 40 in which the first transaction is downgraded such that it no longer continue batch processing redo information.

44. The system of claim 40 in which the first transaction continues to batch process redo information.

45. The system of claim 35 in which the set of redo information is optimized before being persisted.

46. The system of claim 45 in which the set of redo information is optimized by collapsing redo information items to remove intermediate changes to data items.

47. The system of claim 35 in which the set of redo information is batch persisted by writing to a redo log on disk.

48. The system of claim 35 in which the set of one or more redo information items is persisted as a single redo record.

49. The system of claim 35 in which undo information is not persisted.