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.
Harry Oppenheimer was the chairman of Anglo American Corporation for a quarter of a century and chairman of De Beers Consolidated Mines for 27 years until he retired from those positions in 1982 and 1984 respectively.