Synonyms with the Same Name

In an ANSI-compliant database, the owner.synonym combination must be unique among all synonyms, tables, views, and sequences. You must specify owner when you refer to a synonym that you do not own, as in this example:

CREATE SYNONYM emp FOR accting.employee  

In a database that is not ANSI-compliant, no two public synonyms can have the same identifier, and the identifier of a synonym must also be unique among the names of tables, views, and sequences in the same database.

The owner.synonym combination of a private synonym must be unique among all the synonyms in the database. That is, more than one private synonym with the same name can exist in the same database, but a different user must own each of these synonyms. The same user cannot create both a private and a public synonym that have the same name. For example, the following code generates an error:

CREATE SYNONYM our_custs FOR customer;
CREATE PRIVATE SYNONYM our_custs FOR cust_calls;-- ERROR!!!

A private synonym can be declared with the same name as a public synonym only if the two synonyms have different owners. If you own a private synonym, and a public synonym exists with the same name, the database server resolves the unqualified name as the private synonym. (In this case, you must specify owner.synonym to reference the public synonym.) If you use DROP SYNONYM with the unqualified synonym identifier when your private synonym and the public synonym of another user both have the same identifier, only your private synonym is dropped. If you repeat the same DROP SYNONYM statement, the database server drops the public synonym.