``limit'' in Oracle?

Hi,

I'm newbie at Oracle database. I want to get some part of data from Oracle database. I did follow SQL sentence in Oracle and it works. But it's very slow to get the result because the table is very huge. Is there more fast way to get result? I use ``limit'' function in MySQL for this case but I don't know how to do this in Oracle.

select * from

    ( select rownum as mynum, * from big_log_tab where ip like '2%')     where mynum between 100 and 110 order by datetime

Sorry for short English but I am really waiting for a reply for this posting. Thank you a lot!

-- 
Brian Lee - http://www.senux.com/