Hi Tony,

This is a good question and the answer is.......it all depends 🙂

If you go with your first solution, yes it would affect processing and size and you'd be best keeping them as properties of attributes or placing them in their own display folder (so as not to destroy a coherent UI for the users) (there's a useful article on attribute properties here: http://www.bidn.com/blogs/DustinRyan/bidn-blog/2087/defining-member-properties-for-an-attribute-in-ssas-2008).

If you go with your second solution (which I would lean towards, what with 100+ columns) then you could store this separate dimension as ROLAP. This would mitigate the processing/storage issue at the sacrifice of query performance. It all depends how many of these "certain" users there are and how often they are planning to run queries against this data.

Another thing that you might consider is that OLAP may not be the best technology for this. Cubes are designed for aggregation, if you are displaying a product column for, say, serial number then what analytical gain can be had? Perhaps if these users want to see things at certain grains it would be better to create a report and then define a reporting action in the cube so they can see this detail if they need to? That way it keeps them using excel to do initial analysis and then can show them more detail if they need it. This would solve both problems of cube processing/size and query performance. At this point I suppose it would also be worth mentioning drillthrough actions which would give you this functionality but also give you the problems in solutions 1 and 2.

So yeah, it depends.