Logical Replication

Logical replication consists of logical decoding and data replication. Logical decoding extracts transaction-level logical logs. The service or database middleware parses the logs and replicates data. GaussDB can periodically synchronize data to heterogeneous databases using the data migration tool. However, it does not support real-time data replication and cannot meet the requirements for real-time data synchronization between heterogeneous databases. To this end, GaussDB provides the logical decoding feature to parse Xlogs and generate logical logs for the target database to parse in real time, implementing data replication. This feature lowers the requirements on the target database, supporting data synchronization between heterogeneous databases and between homogeneous but different databases, and allows data to be read and written during data synchronization, achieving low data synchronization latency. Figure 1 shows the implementation. This section describes only logical decoding.