SQL & PL/SQL

There's a fairly popular Ordered Hint example on the web as follows:

<CODE>
select /*+ ordered use_nl(bonus) parallel(e, 4) */
e.ename,
hiredate,
b.comm
from
emp e,
bonus b
where
e.ename = b.ename
;
</CODE>

I would like to know what the "parallel(e, 4)" clause does. Where does the "4" come from? What is "parallel" here?

I also have another question: If I have 5 tables--T_OREGON, T_UTAH, T_VIRGINIA, T_TEXAS, and T_OKLAHOMA--lined up in a join right behind a FROM, coming in at row counts of

T_OREGON: [a lot of rows; a lot more than T_UTAH]
T_UTAH: [smaller than T_OREGON] 40550 rows
T_VIRGINIA: 14 rows
T_TEXAS: 66 rows
T_OKLAHOMA: 8 rows

like so:

...from T_OREGON or, T_UTAH ut, T_VIRGINIA va, T_TEXAS tx, T_OKLAHOMA ok...


my question is, if an Ordered hint can be used here, is it that the smallest table (in this case T_OKLAHOMA) gets placed first in the join and the rest of the table ascension in the join doesn't matter? Or is it that T_OKLAHOMA gets placed first in the join, followed by T_VIRGINIA [at 14 rows], followed by T_TEXAS, T_UTAH, and finally T_OREGON?

Thank you for any help that you can provide.