Giving monetdb a fair chance

Franck Routier franck.routier at axege.com
Thu Jul 11 11:58:15 CEST 2013


Hi,

Le 11/07/2013 11:20, Martin Kersten a écrit :
>
> Without insight into your benchmark queries and database schema for 
> the row stores, little can be said.
Sure... but I just wanted to get past the obvious problems before going 
into the details.
> A typical pitfall could be to use row-based queries such as "SELECT * 
> FROM tableexpr", which would call
> for expensive tuple reconstruction of all columns.
No, we don't. In fact, Mondrian doesn't, to be precise.
> Another explanation can come from a multidimensional
> index maintained in a rowstore to speedup grouping.
We did not declare any index in MonetDB. Maybe this is the problem ?
> Last but not least, it could be grouping order or
> skewed data distribution.
>
> MonetDB provides some tools to see where time goes, which may give a 
> hint.
> http://www.monetdb.org/Documentation/Manuals/MonetDB/Profiler/Stethoscope
I will investigate and try to find out what is happening. I'll come back 
with more information.
>
> Your table sizes reported is not extreme at all.
That is what I thought... and why I'm asking, as my current results are 
really not expected...

Regards,

Franck
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