Patents - 11921748

11,921,748 - Method and apparatus for using representations of blocks of data when continuously comparing two databases which are actively being kept synchronized

An automated method and apparatus are provided for comparing a source database and a target database that are intended to be kept in synchronization with each other. An application processes database changes that are posted to the source database and replicated to the target database. The source database and the target database are made up of blocks of data. Blocks of data from the source database having database changes are collected. These blocks of data are replicated to the target database. Blocks of data from the target database that correspond to the blocks of data from the source database having database changes are read. Representations of the blocks of data from the source database having database changes are compared to representations of blocks of data from the target database that correspond to the blocks of data from the source database having database changes. A corrective action is performed when the comparison indicates that the representations of the blocks of data from the source database having database changes do not match the representations of blocks of data from the target database that correspond to the blocks of data from the source database having database changes. A similar process is performed using “before images” of blocks of data from the source database having database changes and then comparing representations of these “before images” to representations of “current images” of blocks of data from the target database that correspond to the before images of blocks of data from the source database having database changes.