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;