[Monetdb-developers] join performance issue!

Martin Kersten Martin.Kersten at cwi.nl
Tue Jul 25 20:27:26 CEST 2006



Stefan Manegold wrote:
> Dear all,
> 
> 
> - We should consider making this BATpropcheck in BATjoin and BATleftjoin
>   configurable from the outside, e.g., by adding an extra optional argument
>   to join() to request to skipping the BATpropcheck.
> 
Instead of pollution of the calling interface, I think we should inject
an explicit request to check/enforce properties. This one might also be 
focussed on those properties of interest according to the optimizer at
that point.

In M5:
   b:= algebra.join(BAT,BAT);
   bat.setProperties(b);

   ...
   bat.checkDenseProperty(b);
   bat.checkOrderProperty(b);
   bat.checkKeyProperty(b);

But first, assess the use of the join(bat,bat) in our controlled
code base. Please report on this.

regards, Martin




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