Re: Is it safe to switch off cost based optimizing?

In article <outputD356Kw.5s0_at_netcom.com>, output_at_netcom.com (Output Services) writes:

|> Our primary use of Oracle is to extract several million records at a
|> time from a set of tables, where extraction order is critical.
|>
|> Using the "order by" clause usually causes Oracle to do a full table sort,

Is that true? I thought Oracle did the ORDER BY after any SELECTs, hence some confusion when using things like,

             '... WHERE ROWNUM < 10 ORDER BY item_date DESC'

to get the 10 most recent 'ITEM's and finding instead that I've got the *first* 10 'ITEM's in reverse order.

I'm just curious.

|> Marty (output_at_netcom.com)

Paul Kennedy (Paul.z.h.k.a.8.Kennedy_at_zhflur.ubs.ubs.ch) Received on Mon Jan 30 1995 - 15:04:53 CET