It realy depends what you really want to do with the column,


LONG datatype columns are used in the data dictionary to store the text of view definitions. You can use LONG columns in SELECT lists, SET clauses of UPDATE statements, and VALUES clauses of INSERT statements

CLOBs participate fully in transactions. Changes made to a CLOB value by the DBMS_LOB package, PL/SQL, or the OCI can be committed or rolled back. However, CLOB locators cannot span transactions or sessions

So clearly you need to know what you are trying to accomplish here.