Patent ID: 8108343
Filing Date: 2012-01-31
Classification: G06F

Abstract:
1. A method implemented at least in part by a computer, the method comprising: accessing a data structure that includes a history of duplication schemas, each duplication schema indicating a set of database fragments that duplicate one or more database records, each database fragment logically associated with a log, at least two database fragments associated with different logs, each log including information that indicates changes made, if any, in its associated database fragment or fragments, the history including time ranges in which the duplication schemas were valid; determining, via the data structure, a set of logs that were potentially written to during a range of time of the time ranges in which the duplication schemas were valid, the range of time having a start time and an end time; determining a set of logs that are currently available; determining whether the set of logs that are currently available includes change information corresponding to the set of logs that were potentially written to during the range of time, the change information indicating changes that were made to the database fragments during the range of time; filtering duplicate data changes to obtain non-duplicative data changes including only one of each change from the change information indicating changes that were made to the database fragments during the range of time, the duplicate data changes being determined using logical timestamps and identifiers of the respective duplication schemas; and creating a single data change stream that includes the non-duplicative data changes.