Oracle provides alter table syntax to modify data columns in-place in this form: alter table table_name modify column_name datatype; If you are brave you can use a single alter table syntax to modify multiple columns:
PRINCETON, N. J., Feb. 18--Dr. J. Robert Oppenheimer, the nuclear physicist, died here tonight at the age of 62. A spokesman for the family said Dr. Oppenheimer died at 8 o'clock in his home on the grounds of the Institute for Advanced Study. He had been ailing since early last year with cancer of the throat.
Oppenheimer's critics have accused him of equivocating between 1949, when he opposed the development of the hydrogen bomb, and 1951, when he supported it. Some have made this a case for reinforcing their opinions about his moral inconsistency.