Example 1: Enabling and Disabling Transaction Starting

    In interactive or dynamic SQL, the following SET command can
    be used to disable or enable transactions starting by the SQL
    interface. The parameter to the SET command is a string literal
    or host variable containing the keyword 'INTERNAL' or 'EXTERNAL'.

    SQL> SET COMPOUND TRANSACTIONS 'internal';
    SQL> CALL START_TXN_AND_COMMIT ();
    SQL> SET COMPOUND TRANSACTIONS 'external';
    SQL> CALL UPDATE_EMPLOYEES (...);