How to track change data capture log history or CDC log history, and computer programs (tracking change data capture log history)

摘要

PROBLEM TO BE SOLVED: To take a first snapshot of a source system and derive a set of key / value pairs reflecting the first snapshot. A mirror operation of a source system is performed to acquire a CDC change operation. The method obtains a first CDC log as a first sequence of key / value pairs. A second snapshot of the source system is taken and a set of key / value pairs is derived, which reflects the second snapshot. The first sequence of key / value pairs is compared to a set of key / value pairs to derive a modified CDC operation and captured as a set of key / value pairs. Modification CDC operations represent modifications to be performed with respect to the first sequence of key / value pairs. The second CDC log is acquired as a second sequence of key / value pairs. The modified CDC operation ensures that the second sequence of key / value pairs is coherent with the set of key / value pairs. [Selection diagram] FIG. 5