The database, and every table, view, index, procedure, and synonym in it, has an owner. The owner of an object is usually the person who created it, although a user with the DBA privilege can create objects to be owned by others.
The owner of an object has all rights to that object and can alter or drop it without additional privileges.
For Generalized Key (GK) indexes, ownership rights are handled somewhat differently than they are for other objects. Any table that appears in the FROM clause of a GK index cannot be dropped until that GK index is dropped, even when someone other than the creator of the table creates the GK index. For more information, refer to Using GK Indexes in a Data-Warehousing Environment.