> All in all, I think the best solution would be the one I wrote in my
> last reply to this list:
>
> create an index on A in the direction you want in order to return
> the first 10 rows quickly.
>
> Use the first 10 rows query as a derived table.
>
> Select from that derived table and order by B.
>
>
> I would like to know if this helps :-)

A quick personal test reveals this to work great -- on a table with
3+ million rows, doing the normal select ORDER BY A DESC, B ASC
takes almost 2 minutes on my PC, the first time, just over 30 secs
after that (cache effect).

The derived table select takes milliseconds.

Syntax:

select
*
from
( select first 10 * from
CSV_DATA_TEST_2
order by C_INT desc) as first_10
order by first_10.c_float asc


So, IF you really want such a thing, I suggest you use this method :-)


With regards,

Martijn Tonies
Upscene Productions
http://www.upscene.com

Download Database Workbench for Oracle, MS SQL Server, Sybase SQL
Anywhere, MySQL, InterBase, NexusDB and Firebird!

Database questions? Check the forum:
http://www.databasedevelopmentforum.com