When an extract user does a SAVEWORK, the changed data will be saved to the extract. The
unchanged data will still be read via pointers back to the master DB. When appropriate, the changes made to the extract can be
issued, that is, written back to the parent database, or
aborted (dropped), which means they will be deleted from the extract. Also, the extract can be
refreshed, that is, updated with changes made to the parent only (which itself may actually have been made in another extract). Alternatively, an extract can be
fully refreshed, that is, updated with changes made from all its extract ancestors.