BTW. I thought this was a really fun problem. Best I've seen on the forums in weeks.
I have an idea for another way to solve it that might be just a tad faster than my rCTE, which I'm betting will beat the pants off the RBAR UPDATE that other forum suggested. I'm talking about the rCTE I already posted that is.
Setting up a performance test harness might be a bit of a challenge. Since you have piqued my interest, I may continue on it for a bit.
Also, about the note where I indicated the product combinations present must include all permutations. I have a way around that now also, in case you need it.
My thought question: Have you ever been told that your query runs too fast?
My advice:
INDEXing a poor-performing query is like putting sugar on cat food. Yeah, it probably tastes better but are you sure you want to eat it?
The path of least resistance can be a slippery slope. Take care that fixing your fixes of fixes doesn't snowball and end up costing you more than fixing the root cause would have in the first place.
Need to UNPIVOT? Why not CROSS APPLY VALUES instead?[/url]
Since random numbers are too important to be left to chance, let's generate some![/url]
Learn to understand recursive CTEs by example.[/url]
[url url=http://www.sqlservercentral.com/articles/St