SQL> set timing on
SQL> set autotrace traceonly
SQL> insert into rd
2 select
3 (dbms_random.value(1,1.99999999999999999999999999999999999999)) r_id,
4 dbms_random.string('U',20) r_string from dual
5 connect by level <=100000
6 /
source : https://community.oracle.com/thread/3696816