Tables, structures, views, pools and clusters formed a common namespace up to Release 4.0. As of Release 4.0, data elements also lie in this namespace.
When a data element is created, there is a check whether a table, structure, view, pool or cluster already exists with the same name and vice versa. If this is the case, the object cannot be created.
Existing data elements for which a table, structure, view, pool or cluster already exists with the same name are renamed.
This action is in preparation for the function planned for 4.0C in which you will be able to access data elements in ABAP programs as types.
The data elements are automatically renamed in the customer namespace during the upgrade. The new name for a data element is the old name, filled up to the 10th place with underlining, and with a "D" added to the 11th place. For example, data element ZD3456789 would be renamed ZD3456789_D.
Whether or not data elements are affected and which data elements are renamed in the customer namespace is determined during the upgrade with messages in LOGFILE RADDREXE.<Systemname>. Since data element names are meaningless for operation in 3.0, the customer normally does not have to take any actions concerning the renaming of a data element.
However, if you do not agree with a proposed name, you can adjust it after the upgrade. To do so, copy the renamed data element to the required name in the Dictionary maintenance routine (SE11). Find all uses of the data element with Utilities -> Where-used list in the display of the data element. Adjust the uses to the new name and then delete the renamed data element automatically.