Re: ORDER BY question

baoqinye_at_gmail.com wrote:
> The architecture group of our company has told us to avoid using ORDER
> BY in our queries. Their reasons are:
>
> - In 10G, order by is incredibly inconsistent. They had an example with
> only 2 rows of data that was extremely slow. Even if it looks like it
> works alright, it's not guaranteed to, and we can't predict when
> it'll fail. That instability is one of the main reasons against it.
>
> - ORDER BY a primary key, especially when the primary key is not used
> in the where clause, has the worst performance and is definitely to be
> avoided.
>
> Is this true?

Complete and total rubbish.

Any statement such as they made ... not backed up with a 10053 trace is just personal opinion.

ORDER BY is expensive ... but "expensive" is a relative term. As others have said ... get the metrics.

And if ORDER BY is ever the issue then look into implementing SORTED HASH CLUSTERS.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org