Views can depend on other views or tables. Procedures can depend on other procedures, views, or tables. These dependencies can be thought of as an ownership chain.
Typically, the owner of a view also owns its underlying objects (other views and tables), and the owner of a stored procedure owns all the procedures, tables, and views referenced by the procedure.
A view and its underlying objects are usually all in the same database, as are a stored procedure and all the objects it references; however, this is not required. If objects are in different databases, a user wanting to use the view or stored procedure must be a valid user or guest user in all of the databases containing the objects. This prevents users from accessing a database unless the database owner has authorized it.
When a user who has been granted execute permission on a procedure or view uses it, Adaptive Server does not check permissions on any of the underlying objects if:
These objects and the view or procedure are owned by the same user, and
The user accessing the view or procedure is a valid user or guest user in each of the databases containing the underlying objects.
However, if all objects are not owned by the same user, Adaptive Server checks object permissions when the ownership chain is broken. That is, if object A references object B, and B is not owned by the user who owns object A, Adaptive Server checks the permissions for object B. In this way, Adaptive Server allows the owner of the original data to retain control over who is authorized to access it.
Ordinarily, a user who creates a view needs to worry only about granting permissions on that view. For example, say Mary has created a view called auview1 on the authors table, which she also owns. If Mary grants select permission to Sue on auview1, Adaptive Server allows Sue to access it without checking permissions on authors.
However, a user who creates a view or stored procedure that depends on an object owned by another user must be aware that any permissions he or she grants depend on the permissions allowed by those other owners.
