Although you can use the SchemaManager API directly, Oracle recommends that you create a TableCreator class and use its API (which, in turn, uses the SchemaManager). The TableCreator class owns one or more TableDefinition classes (one for each database table) and the TableDefinition class owns one or more FieldDefinition classes (one for each field).
The TableDefinition class lets you specify a database table schema in a generic format. At run time, TopLink uses the session associated with your TopLink project to determine the specific database type, and uses the generic schema to create the
appropriate tables and fields for that database.