[MonetDB-users] Profiling queries

Niels Nes Niels.Nes at cwi.nl
Wed Dec 5 09:12:56 CET 2007


On Wed, Dec 05, 2007 at 01:09:48AM -0700, m h wrote:
> On Dec 5, 2007 12:46 AM, Niels Nes <Niels.Nes at cwi.nl> wrote:
> 
> > All of the groupby columns are varchar (except the last bigint). I'm just
> > guessing but do you see high numbers in your trace for the
> > group.* calls? (The numbers are listed a before the statement being executed).
> >
> 
> Again, I'll look at this after rest, but how do you get around group
> by when your aggregating data?
I'm just looking where the cost come from. Maybe our groupby on strings isn't
strong enough. Usually grouping on group by attributes with low ordinality 
(low number of different values in the type) is better.

Niels
> 
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-- 

Niels Nes, Centre for Mathematics and Computer Science (CWI)
Kruislaan 413, 1098 SJ Amsterdam, The Netherlands
room C0.02,  phone ++31 20 592-4098, fax ++31 20 592-4312
url: http://www.cwi.nl/~niels   e-mail: Niels.Nes at cwi.nl




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