When resolving references to an object, Oracle Database uses a public synonym only if the object is not prefaced by a schema and is not followed by a database link. However each user must have appropriate privileges on the underlying object in order to use the synonym. Public synonyms are accessible to all users. Specify PUBLIC to create a public synonym. For information about editioned and noneditioned objects, see Oracle Database Development Guide. For public synonyms, the default is NONEDITIONABLE. For private synonyms, the default is EDITIONABLE. Use these clauses to specify whether the synonym is an editioned or noneditioned object if editioning is enabled for the schema object type SYNONYM in schema. Restriction on Replacing a Synonym You cannot use the OR REPLACE clause for a type synonym that has any dependent tables or dependent valid user-defined object types. Use this clause to change the definition of an existing synonym without first dropping it. Specify OR REPLACE to re-create the synonym if it already exists. You can refer to synonyms in the following DDL statements: AUDIT, NOAUDIT, GRANT, REVOKE, and COMMENT. You can refer to synonyms in the following DML statements: SELECT, INSERT, UPDATE, DELETE, FLASHBACK TABLE, EXPLAIN PLAN, and LOCK TABLE. Appropriate privileges must be granted to a user before the user can use the synonym. However, synonyms are not a substitute for privileges on database objects. Synonyms permit applications to function without modification regardless of which user owns the table or view and regardless of which database holds the table or view. Synonyms provide both data independence and location transparency. A synonym places a dependency on its target object and becomes invalid if the target object is changed or dropped. Use the CREATE SYNONYM statement to create a synonym, which is an alternative name for a table, view, sequence, operator, procedure, stored function, package, materialized view, Java class schema object, user-defined object type, or another synonym.
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