Syntax options:

    WAIT |NOWAIT

    Determines what your transaction does when it encounters a locked
    row. The default is WAIT.

    o  If you specify WAIT, the transaction waits for other
       transactions to complete and then proceeds. If you prefer,
       you can specify that the transaction proceeds after a certain
       time interval instead of waiting for other transactions to
       complete. You can specify the timeout interval value after
       the WAIT keyword. The timeout interval value is expressed in
       seconds.

    o  If you specify NOWAIT, your transaction returns an error
       message when it encounters a locked row.