In SQL:1999 there's a ROW_NUMBER function, but it's not yet included (you'll have to wait until V2R5 in December).
But you can achieve the same result using
select * from table
qualify sum(1) over (order by col
rows unbounded preceding) <= 10
or
qualify rank() over (order by col) <= 10
As QUALIFY is no standard SQL you'll have to use a derived table to be ANSI compliant:
select ... from
(select ..., rank() over (order by col) AS rownum
from table) dt
where rownum <= 10
If you don't care about the order (and about ANSI SQL) use a SAMPLE clause, this will be the fastest way:
sel * from table sample 10
Dieter