SQL> CREATE TABLE myLongTable1 (id NUMBER,long_data LONG);
Table created.
SQL>
SQL> INSERT INTO myLongTable1 VALUES (100,RPAD('A',200000,'A'));
1 row created.
SQL>
SQL> ALTER TABLE myLongTable1 MODIFY (long_data CLOB);
Table altered.
SQL>
SQL> drop table myLongTable1;
Table dropped.