The mode refers primarily to the start positions of your data items. You can create a dictionary either in relative or absolute mode.
• Relative mode
- Use relative mode when designing a new data file; you do not normally want "holes" (unused space between items) in your data files, as this will increase the size of the file.
- The record type, if present, is always the first item in every record.
- ID items, if any, are always located after the record type (and other ID Items defined at a higher level).
- Each data item will be placed after all defined ID items (even those defined at a higher level than the record) in the record.
- There are no gaps or "holes" between items.
- As items are added, inserted, modified, or deleted, other items are automatically moved as needed to maintain the above arrangement.
- Changing the starting position of an item will move it and any following items to give the implied relative arrangement.
• Absolute mode
- Use absolute mode to create a dictionary from an existing data file.
- The record type, ID items and data items can be positioned at any location in a record.
- All items will remain in their assigned locations, unless specifically moved by the user.
- When inserting or adding an item, there must be room (i.e., a "gap") for the item at the specified location.
- When items are deleted, gaps may be created.
- When an item's starting position or length is changed, room for the item must exist.