Online Documentation for Advanced Data Import for RAD Studio VCL
property OnNeedCommit: TNotifyEvent;
The OnNeedCommit event takes place after importing a number of records, defined in the CommitRecCount property, or when the import is finished, if the CommitAfterDone is true. If neither of these properties are defined, the OnNeedCommit event will never take place.
Note that you should process the event manually to commit writing data to the dataset.