Re: Help needed with slow union join

"Vince" <vinnyop_at_yahoo.com> wrote:

> If there is no overlap in the data between the 2 selects, try using
> UNION ALL instead of UNION.

What is the technical rationale for doing such a thing?

Paul...

-- 

plinehan __at__ yahoo __dot__ __com__

XP Pro, SP 2, 

Oracle, 9.2.0.1.0 (Enterprise Ed.)
Interbase 6.0.1.0;

When asking database related questions, please give other posters 
some clues, like operating system, version of db being used and DDL.
The exact text and/or number of error messages is useful (!= "it didn't work!").
Thanks.
 
Furthermore, as a courtesy to those who spend 
time analysing and attempting to help, please 
do not top post.