CONSISTENT CLIENT-SIDE CACHE

• US 20080098173A1
• Filed: 10/19/2007
• Published: 04/24/2008
• Est. Priority Date: 10/20/2006
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: CHIDAMBARAN, Lakshminarayanan, LAHIRI, Tirthankar, BASTAWALA, Mehul, KRISHNASWAMY, Srinath, SINHA, Bipul, LOAIZA, Juan, VEMURI, Srinivas
• Granted Patent: US 9,697,253 B2
• Time in Patent Office: Days
• US Class Current: 711/118
• CPC Class Codes: G06F 16/24552 Database cache management

Abstract

A method, system, and computer program product is disclosed for caching results in a client-side cache. Embodiments of a method, a system, and a computer program product are disclosed that associate a first snapshot of a database with a client that indicates a state of the database after a last database request by the client, and indicate any number of invalid cached results in the client cache for the client based upon the first snapshot. In some embodiments, the method further includes receiving a second snapshot that indicates a state of the database upon receipt of a database server request by the client, and updating the first snapshot with the second snapshot.

Claims

1. A method for caching results in a client-side cache, comprising:

associating a first snapshot of a database with a client, wherein the first snapshot indicates a state of the database after a last database request by the client; and

indicating any number of cached results as being invalid in the client-side cache for the client based upon the first snapshot.

2. The method of claim 1, further comprising:

receiving a second snapshot, wherein the second snapshot indicates a state of the database upon receipt of a database server request by the client; and

updating the first snapshot with the second snapshot.

3. The method of claim 1, further comprises:

invalidating some or all of the any number of cached results that have been indicated as invalid for a client session, wherein the some or all of the cached results includes cached results for the client session that relate to uncommitted database changes made by the client with the client session.

4. The method of claim 2 further comprises:

receiving any number of cached result identifiers, wherein the any number of cached result identifiers relate to transactions that occurred between the first snapshot and the second snapshot; and

invalidating the any number of invalid cached results associated with the any number of cached result identifiers.

5. The method of claim 1, further comprising:

storing the first snapshot with a cache manager, wherein the cache manager accesses the client-side cache.

6. The method of claim 4, wherein the any number of cached result identifiers are query ids.

7. The method of claim 1, wherein the invalid cached results further comprises invalid results due to a change in environment settings.

8. The method of claim 1, wherein the invalid cached results further comprises invalid cached result identifiers for database changes made by transactions other than those issued by the client.

9. The method of claim 1, wherein the invalid cached results further comprises at least one cached result identifier associated with a snapshot of the database at creation time of the at least one invalid cached result identifier.

10. The method of claim 1, wherein the database is a database cluster.

11. The method of claim 1, further comprising:

performing garbage collection after abnormal termination of the client.

12. The method of claim 1, wherein the invalid cached results are retained by the client along with a snapshot of the database at a creation time of an invalid cached result, wherein the invalid cached results are result sets associated with invalid cached result identifiers.

13. The method of claim 1, further comprises a maximum cache lag, wherein the cache is not accessed if the maximum cache lag is exceeded.

14. The method of claim 1, further comprising:

determining if a query result needs to be cached, wherein the query result is designated to be cached at a database server using one or more of the following;

a data description language command, a query command or a database application programming interface; and

caching the query result based upon the determining.

15. A computer program product comprising a computer usable medium having executable code to execute a process for implementing a client cache in a computing system, the process comprising:

associating a first snapshot of a database with a client, wherein the first snapshot indicates a state of the database after an interaction with the database by the client; and

invalidating any number of invalid cached results in the client cache for the client based upon the first snapshot.