Improving Society Through Innovation

7,882,062 - Synchronization of plural databases in a database replication system when replication is slower than the synchronization process

Abstract:

A target database is synchronized with a source database and the source database is replicated to the target database in a database replication system. The source database is on-line during the synchronization. The source database is located at a first node of the system, and the target database is located at a second node of the system. Changes in the source database are replicated to the target database by sending a replication stream from the first node to the second node. Successive blocks of data are sent from the first node to the target database to synchronize or resynchronize the target database with the source database. Each block of data includes one or more rows of data. The successively sent blocks of data define a loading stream. The successively sent blocks of data are posted into the target database when the replication stream is occurring slower than the loading stream. Synchronization or resynchronization thereby occurs simultaneously with replication.