How to enable tracing for another session, for the event 10046?

EXEC DBMS_SYSTEM.set_ev(si=>123, se=>1234, ev=>10046, le=>8, nm=>'');

To disable the 10046 trace:

EXECUTE dbms_system.set_ev (123,1234,10046, 0, '');

How to create fast a table with 1 million rows

  create table test1
  as
  select rownum rn, mod(rownum,1000) mod1 ,  mod(rownum,90) mod2
 from dual
 connect by level <=1000000;