lsllcm wrote:
> Thanks for all your help.
>
> I have another question to consult.
>
> I have a table T1 with 900,000 rows, and join with 2-3 other tables,
> and retrieve out about 300,000 rows, then do "order by" operations. At
> last get the first 100 rows. It causes many direct path write and read
> events.
>
> Do you have any ideas about how to optimize this kind of sql?
When you say ... retrieve out about 300K rows ... surely no one is
actually reading 300K rows. So what is it you really need and can
the query be rewritten to only retrieve the rows actually required?
--
Daniel A. Morgan
http://www.psoug.org
damorgan_at_x.washington.edu
(replace x with u to respond)
Received on Mon Nov 21 2005 - 10:06:52 CST
