Performance impact I doubt you could even detect.
You will consume a little more space.
SQL> create table t1 ( x int, y int, z char(50));
Table created.
SQL> create table t2 ( x int, y int, z char(50)) rowdependencies;
Table created.
SQL>
SQL> set timing on
SQL> insert into t1 select rownum, rownum, rownum
2 from dual
3 connect by level <= 100000;
100000 rows created.
Elapsed: 00:00:00.22
SQL>
SQL> insert into t2 select rownum, rownum, rownum
2 from dual
3 connect by level <= 100000;
100000 rows created.
Elapsed: 00:00:00.14
SQL>
SQL> begin
2 for i in 1 .. 10000 loop
3 insert into t1 values (i,i,i);
4 commit;
5 end loop;
6 end;
7 /
PL/SQL procedure successfully completed.
Elapsed: 00:00:00.59
SQL>
SQL> begin
2 for i in 1 .. 10000 loop
3 insert into t2 values (i,i,i);
4 commit;
5 end loop;
6 end;
7 /
PL/SQL procedure successfully completed.
Elapsed: 00:00:00.60
SQL>