Susan Shio Cheng

US Patent:

20110072217, Mar 24, 2011

Filed:

Sep 18, 2009

Appl. No.:

12/562928

Inventors:

Chi Hoang - Palo Alto CA, US
Tirthankar Lahiri - Palo Alto CA, US
Marie-Anne Neimat - Atherton CA, US
Chih-Ping Wang - Palo Alto CA, US
John Miller - Los Altos CA, US
Dilys Thomas - Redwood City CA, US
Nagender Bandi - Redwood City CA, US
Susan Cheng - Cupertino CA, US

International Classification:

G06F 12/08
G06F 12/00

US Classification:

711130, 711118, 711E12001, 711E12017, 707E17045

Abstract:

A plurality of mid-tier databases form a single, consistent cache grid for data in a one or more backend data sources, such as a database system. The mid-tier databases may be standard relational databases. Cache agents at each mid-tier database swap in data from the backend database as needed. Consistency in the cache grid is maintained by ownership locks. Cache agents prevent database operations that will modify cached data in a mid-tier database unless and until ownership of the cached data can be acquired for the mid-tier database. Cache groups define what backend data may be cached, as well as a general structure in which the backend data is to be cached. Metadata for cache groups is shared to ensure that data is cached in the same form throughout the entire grid. Ownership of cached data can then be tracked through a mapping of cached instances of data to particular mid-tier databases.

US Patent:

20130198249, Aug 1, 2013

Filed:

Mar 13, 2013

Appl. No.:

13/799572

Inventors:

Oracle International Corporation - Redwood Shores CA, US
Tirthankar Lahiri - Palo Alto CA, US
Marie-Anne Neimat - Atherton CA, US
Chih-Ping Wang - Palo Alto CA, US
John E. Miller - Los Altos CA, US
Dilys Thomas - Palo Alto CA, US
Nagender Bandi - Foster City CA, US
Susan Cheng - Cupertino CA, US

Assignee:

Oracle International Corporation - Redwood Shores CA

International Classification:

G06F 17/30

US Classification:

707825

Abstract:

A plurality of mid-tier databases form a single, consistent cache grid for data in one or more backend data sources, such as a database system. The mid-tier databases may be standard relational databases. Cache agents at each mid-tier database swap in data from the backend database as needed. Ownership locks maintain consistency in the cache grid. Cache agents prevent database operations that will modify cached data in a mid-tier database unless and until ownership of the cached data can be acquired for the mid-tier database. Cache groups define what backend data may be cached, as well as a general structure in which the backend data is to be cached. Metadata for cache groups is shared to ensure that data is cached in the same form throughout the entire grid. Ownership of cached data can then be tracked through a mapping of cached instances of data to particular mid-tier databases.