create table dropme_t(col1 integer, col2 integer);
Table created

merge into dropme_t t
using(select power(2, rownum) v from dual connect by level < 10) s
on (1=2)
when not matched then
  insert (col1, col2)
  values(s.v, s.v)
;
9 rows merged

select * from dropme_t
;
                                   COL1                                    COL2
--------------------------------------- ---------------------------------------
                                      2                                       2
                                      4                                       4
                                      8                                       8
                                     16                                      16
                                     32                                      32
                                     64                                      64
                                    128                                     128
                                    256                                     256
                                    512                                     512
9 rows selected

rollback;
Rollback complete

insert into dropme_t(col1, col2)
with t as (select power(2, rownum) v from dual connect by level < 10)
select v,v from t;
9 rows inserted
select * from dropme_t
;
                                   COL1                                    COL2
--------------------------------------- ---------------------------------------
                                      2                                       2
                                      4                                       4
                                      8                                       8
                                     16                                      16
                                     32                                      32
                                     64                                      64
                                    128                                     128
                                    256                                     256
                                    512                                     512
9 rows selected

rollback;
Rollback complete

begin
  for i in
  (select power(2, rownum) v from dual connect by level < 10
  ) loop
	insert into dropme_t (col1, col2)
	values (i.v, i.v);
  end loop;
end;
/
PL/SQL procedure successfully completed

select * from dropme_t
;
                                   COL1                                    COL2
--------------------------------------- ---------------------------------------
                                      2                                       2
                                      4                                       4
                                      8                                       8
                                     16                                      16
                                     32                                      32
                                     64                                      64
                                    128                                     128
                                    256                                     256
                                    512                                     512
9 rows selected

drop table dropme_t purge;
Table dropped

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