Here are steps to set what data types should be converted to. These instructions are for the example giving in the Problem Desciption section above, but can be modified to fit any database platform or data type.
1. Enable Expert Mode in the Options by selecting Settings | Options | General and check 'Expert Mode'.
2. Switch to the MySQL model.
3. In the menu bar, select Expert Mode | Expert Mode Settings | Data Type Conversion Settings.
4. There are two fields. The source should be set to MySQL and the destination to Oracle. Then click on the Load button in the left upper corner to see the data type mapping.
5. Select "BigInt" in the columns Source and change (Press F2) the value of the column Destination to "Number". If the MySQL model is converted to Oracle again, the BigInt data type will be converted to Number.