Extent wizard

Extents are globally defined data collections. In contrast to references and relationships, extents do not belong to an object instance, but can be accessed directly (without accessing an instance before). Thus, extents are the entry points to data in the database. Besides persistent extents, ODABA supports different kinds of transient extents, i.e. extents, which are created at run-time.

• temporary and transient extents
• virtual extents

A detailed description for different collection types is available in ODABA-base documentation topic Reference documentation/ODABA Model reference/Data model/References. For defining new extents, the extent wizard might be called from the class tree after selecting an entry in the [ Extents ] region.

The extent wizard cannot be used for updating extent properties, which has to be done directly in the extent editor form right of the class tree.

The following chapters describe scenarios for defining different types of extents. When confirming changes in the wizard with Finish, the extent definition might be checked using the check button in the toolbar above the extent edit form.