The source Datareplicator reads the update information stored in the system log file and stores it in an extraction information queue file according to the extraction definition. To do this, Datareplicator uses the system log I/O buffer and extraction information queue I/O buffer for extraction. If the source HiRDB is a parallel server, Datareplicator executes extraction processing for each back-end server. For details about each buffer used for extraction, see 4.6.3 Designing the extraction procedure.

The source Datareplicator reads the update information stored in the extraction information queue file for each destination, edits this information if the transaction has been completed, and then sends it to the target system. To do this, Datareplicator uses the extraction information queue I/O buffer for transmission and the update information editing buffer. For details about each buffer used for transmission, see 4.6.4 Designing the transmission procedure.