Patent ID: 7970787
Filing Date: 2011-06-28
Classification: G06F

Abstract:
1. A method for improving access concurrency to information stored in at least one table in a relational database system comprising the steps of: (a) providing a data cache comprising a plurality of cache entries, wherein each cache entry comprises a first data item, a second data item, and a cache entry state identifier identifying a cache entry state; (b) retrieving from the at least one table and storing in a cache entry's first data item a representation of committed information for a user; (c) storing in the cache entry's second data item a representation of changes applied to the committed information, but not yet committed in the database system, wherein the changes are made by execution of one or more modify statements prior to the modify statements being committed in the database system; (d) receiving a request from an agent to access information in the cache entry; and (e) permitting the agent access to only one of the first data item and the second data item, wherein determining which one of the first data item and second data item is accessed is based on the cache entry state identifier and based on a type of a currently-executing modify statement separate from the request and configured to modify the information in the cache entry.