Is this intended or a bug?
This is intended. We see it as way to hide what is beneath thus having header alias as the column name discards the advantage and that's the reason incomplete headers are not generated.
Well that doesn't mean we cannot add an option to generate incomplete headers.
Sorry for the long time to reply on this.
I agree with what you say about the view header alias being a way to hide what is underneath, but sometimes we only need to alias certain view columns and the rest are ok to stay the same as the column names.
Thus (if coding by hand) we do have view creation DDL that aliases some columns (from "below") and the others are just the same as the column names.
So, if you guys do not agree with that, I would like to then request an enhancement request be logged, as you mention in your reply, for a way to indicate that we are ok for only some header alias to be defined and have the DDL contain those aliases, plus column names (as aliases) for columns not so formally aliased.
Thank you & Regards
I logged the enhancement request in the Oracle Bug Database (number 17197493).
Enhancements to Data Modeler can also be requested and voted on in the SQL Developer Exchange https://apex.oracle.com/pls/apex/f?p=43135:1
This enhancement has been implemented in the Early Adopter 2 version of Data Modeler 4.0 which can now been downloaded from http://www.oracle.com/technetwork/developer-tools/datamodeler/downloads/datamodeler-4ea-downloads-1988443.html