The Extractor generates intermediate files on disk to store captured change data. An intermediate file is composed of a data file (.dat) and a transaction file (.trn).
The Server Manager instances on the source and target coordinate to transfer the intermediate files to the Applier. The Applier parses the files and applies the committed changes to the target database. After the Applier sends a confirmation message to the Server Manager instance on the target, the Server Manager purges the intermediate files for which all changes were processed and retains only the intermediate files that contain uncommitted transactional changes.