Variables are persistent across sessions and users. In some cases, best practices dictate that we remove a variable. The DROP and UNSET commands both do this, and function the same way.

Let’s see our current variables:

1 SQL> show variables;

Use DROP to remove a variable:

1 SQL> drop variable v_period_info;

Use UNSET to remove a variable:

1 SQL> unset v_period_name;

Check to make sure those variables are gone:

1 SQL> show variables;