To expose special columns for a selected table
Right-click on the class row in the Tables table and then select the Expose Special Columns for Selected Table command from the popup menu that is displayed.
All special columns in the selected table are then exposed for inclusion in the relational database table; that is, each check box in the Special Columns pane for that table is checked, indicating that the _operation, _tranid, _timestamp, and _edition special columns will be replicated as columns in the relational database table.