Basic Sql performance question

If I have two tables
create table tab1(col1 number, col2 varchar2(50)); create table tab2(col1 number, col2 varchar2(50));

insert into tab1 values (1, 'One');
insert into tab1 values (2, 'Two');
insert into tab1 values (3, 'Three');

insert into tab2 values (3, 'Three');

I want all tuples that are in tab1 but not in tab2. That is, 1, 'One' and 2, 'Two'
The ways I can do this are
1.
Select * from tab1 minus select * from tab2; 2.
Select t1.*
from tab1 t1
where not exists
(select col1 from tab2 where col1 = t1.col1); 3.
Select *
from tab1 t1
where col1 not in (select col1 from tab2); 4. Select t1.*
from tab1 t1, tab2 t2
where t1.col1 = t2.col1(+)
and t2.col1 is null

Which of these four methods is the fastest and in which circumstances? Could someone rank them for me?
Is there a fifth, still better way?
Thanks,
DA Singh Received on Mon Oct 06 2003 - 19:38:03 CEST