I'm getting error when I try to create a table with USER as
the default.
i.e create table test (col1 varchar2(18) default USER);

ERROR at line 1:
ORA-01401: inserted value too large for column

if I expand col1 to varchar2(30) then I won't have this problem. Does this means the length of USER is 30?

Can anyone confirm that the default size for USER is 30.