Ian wrote:

> select * from
> (select
> ...,
> rownumber() over (order by login_timestamp) as rn
> from ...
> ) as a
> where rn between 10 and 30

Well, sounds good. But I have no idea what is the cost of rownumber()
and the subselect if the table grows.

Or better: does it cost more time to create the identity value on every
login (not very often, about 1-2 times per minute) or does it cost more
time to create a subselect on a table with 50.000 entries to fetch 10
rows at the end.

Bernd