If you alter the structure of a view’s underlying tables by adding or deleting columns, the new columns do not appear in a view that is defined using the select * clause unless you drop, and then redefine the view. The asterisk shorthand is interpreted and expanded when the view is first created.
If a view depends on a table or view that has been dropped, the SAP ASE server produces an error message when anyone tries to use the view. If a new table or view with the same name and schema is created to replace the one that has been dropped, the view again becomes usable.
You can redefine a view without redefining other views that depend on it, unless the redefinition makes it impossible for the SAP ASE server to translate any dependent views.