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

  • From: Dominic Brooks <dombrooks@xxxxxxxxxxx>
  • To: <chrisdavid.taylor@xxxxxxxxxxxxxxx>
  • Date: Sat, 6 Aug 2011 06:07:56 +0000

Are the estimates for the plan accurate?
This is key to having properly sized workareas, etc.

See Randolf's post on hash aggregation and workareas:
http://oracle-randolf.blogspot.com/2011/01/hash-aggregation.html

> From: ChrisDavid.Taylor@xxxxxxxxxxxxxxx
> To: greg@xxxxxxxxxxxxxxxxxx
> CC: oracle-l@xxxxxxxxxxxxx
> Date: Fri, 5 Aug 2011 18:50:57 -0500
> Subject: Re: Wow - has anyone used ROW_NUMBER() to get around using a UNION 
> statement when UNION ALL doesn't work??
> 
> Greg, I didn't want to include all that in a general discussion on the list.  
> I've got the plans, trace files and the tkprof outputs.  
> 
> I wanted to gauge interest primarily.  Wolfgang, as an example, asked about 
> HASH GROUP BYs.  I'm not trying to solve a problem as much as discuss an 
> interesting idea.  So I wasn't sure what people might want to see AND not see.
> 
> 
> 
> Sent from my mobile device.  Please ignore any typos or misspellings.
> 
> On Aug 5, 2011, at 3:40 PM, "Greg Rahn" <greg@xxxxxxxxxxxxxxxxxx> wrote:
> 
> > It would be extremely useful when talking about different plans to
> > actually have the output from dbms_xplan.display.
> > 
> > On Fri, Aug 5, 2011 at 1:15 PM, Taylor, Chris David
> > <ChrisDavid.Taylor@xxxxxxxxxxxxxxx> wrote:
> >> 
> >> Doh!
> > 
> > 
> > --
> > Regards,
> > Greg Rahn
> > http://structureddata.org
> > 
> 
> --
> //www.freelists.org/webpage/oracle-l
> 
> 
                                          

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