Example 1: Adding a Comment SQL> ALTER SYNONYM CASH cont> COMMENT IS 'use a different name to avoid confusion with' cont> / 'the domain MONEY'; Example 2: Using Multiple Synonyms and Changing the Referenced Table Using ALTER The following example uses a synonym to reference a table. Later an empty version of the table can be created and the synonym altered to reference this new table. Although similar to using a view definition, the use of synonyms avoid the usage locking of a view. That is, to drop and create a new view requires that no other user references that view, however, the alter synonym does not require exclusive access to the table. SQL> CREATE TABLE t_employees_0001 (...); SQL> CREATE SYNONYM employees FOR t_employees_0001; SQL> CREATE SYNONYM emps FOR employees; SQL> CREATE TABLE t_employees_0002 LIKE t_employees_0001; SQL> ALTER SYNONYM employees FOR t_employees_0002;