Re: Should Oracle outperform PostgreSQL on a complex

Simon Riggs wrote:
> On Sun, 2005-12-18 at 15:02 +1300, Mark Kirkwood wrote:
>
>
>>Yeah - the quoted method of "make a cartesian product of the dimensions
>>and then join to the fact all at once" is not actually used (as written)
>>in many implementations
>
>
> But it is used in some, which is why I mentioned it.
>
> I gave two implementations, that is just (1)
>
>

Sorry Simon, didn't mean to imply you shouldn't have mentioned it - was
merely opining about its effectiveness....

>>- probably for the reasons you are pointing out.
>>I found these two papers whilst browsing:
>>
>>
>>http://www.cs.brown.edu/courses/cs227/Papers/Indexing/O'NeilGraefe.pdf
>>http://www.dama.upc.edu/downloads/jaguilar-2005-4.pdf
>>
>>
>>They seem to be describing a more subtle method making use of join
>>indexes and bitmapped indexes.
>
>
> Which is the option (2) I described.
>

Ok - I misunderstood you on this one, and thought you were describing
the "star transformation" - upon re-reading, I see that yes, it's more
or less a description of the O'Neil Graefe method.

best wishes

Mark