Re: Wow - has anyone used ROW_NUMBER() to get around using a UNION statement when UNION ALL doesn't work??

  • From: Greg Rahn <greg@xxxxxxxxxxxxxxxxxx>
  • To: mwf@xxxxxxxx
  • Date: Mon, 8 Aug 2011 11:37:08 -0700

Mark --  the OP mentioned in the first email all 3 scenarions with
some execution times and other comments.  IMHO this makes it more than
a logical discussion of theory.  My point here is it's very difficult
to comment on the "why" about something without knowing the technical
bits of "what" it is doing.  In this case, the "why" is about the
performance, but the "what" required are the execution plans.


On Mon, Aug 8, 2011 at 9:27 AM, Mark W. Farnham <mwf@xxxxxxxx> wrote:
> In the vast majority of cases I agree with Greg about posting plans.
> However, in this particular case the question is a purely logical
> consideration not based on any particular plans the optimizer is choosing.
> But a little bit more of context may be required.

-- 
Regards,
Greg Rahn
http://structureddata.org
--
//www.freelists.org/webpage/oracle-l


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