AW: SQL : subtotals and total

["BirgittaHauser" <Hauser@xxxxxxxxxxxxxxx>]

Hi,

> > Without an explicit request to ORDER BY, there is nothing for sure to 
> > be /followed by/ anything, regardless of how many times the given 
> > SELECT may *appear* to effect some perceived ordering.

> What you say?

If you need a predefined sequence in your result set, you need to add an
order by clause.
Even if you specify a logical file with right key fields(which is not a good
design because the queries must be executed by the CQE), the optimizer may
use a different access path with an other sequence and consequently the
result is not sorted in the expected way.

The optimizer searches for a way to get the requested data as fast as
possible and if necessary sortes the data after selection.

Mit freundlichen Grüßen / Best regards

Birgitta Hauser

"Shoot for the moon, even if you miss, you'll land among the stars." (Les
Brown)
"If you think education is expensive, try ignorance." (Derek Bok)
"What is worse than training your staff and losing them?  Not training them
and keeping them!"

-----Ursprüngliche Nachricht-----
Von: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] Im Auftrag von David FOXWELL
Gesendet: Thursday, August 07, 2008 09:39
An: Midrange Systems Technical Discussion
Betreff: RE: SQL : subtotals and total



Chuck wrote:

> Without an explicit request to ORDER BY, there is nothing for sure to 
> be /followed by/ anything, regardless of how many times the given 
> SELECT may *appear* to effect some perceived ordering.

What you say?