Modifying Table Descriptors

In the Data Mart definition you can remove existing Table Descriptors and add different ones.You must check out the definition to add, remove, or update Table Descriptors, but not to map, unmap, or remap Table Descriptors.

In the Data Mart instance, you can change the Table Descriptor mappings, which are part of the Data Mart instance, not the definition; see Mapping Table Descriptors to Table Instances. You do not need to check out the definition to modify the mappings.