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 Frederick Oppenheimer, 1908-2000. Harry Oppenheimer was born in Kimberley, the diamond city of South Africa, on 28 October 1908. After completing his primary schooling in Johannesburg, he attended Charterhouse school in England, before going on to study at Christ Church, Oxford, graduating in 1931 in philosophy, politics and economics.