Distributed consistent grid of in-memory database caches

US8401994B2 · kind B2 · utility

Assignee

• Oracle International Corporation · US

Inventors

• Chi-Kim Hoang · Palo Alto, US
• Tirthankar Lahiri · Palo Alto, US
• Marie-Anne Neimat · Atherton, US
• Chih-Ping Wang · Palo Alto, US
• John Miller · Los Altos, US
• Dilys Thomas · Pune, IN
• Nagender Bandi · Foster City, US
• Susan Cheng · Seattle, US

Key dates

• Filing date: Sep 18, 2009
• Grant date: Mar 19, 2013
• Expiry date: Jun 18, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F12/084
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

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.