People ask me a lot what’s new in MDX for Yukon. MDX itself really isn’t all that different, but with the multiple hierarchies in a dimension, there are a lot of implications of MDX that new. One that I was working on with Scott a few days ago had to do with the implication of turning off aggregations for an attribute hierarchy. As soon as you turn off aggregations for the attribute, you suddenly get the default member implied in every single tuple you ever use (where you don’t specifically mention the attribute). So, for example, if you had an attribute with countries and no All member, the first member — say Albania — becomes the default default member. In every expression, unless you specify an explicit country—or reference the entire set of Country.Members — you implicitly get Albania. This is, again, not different from AS2K, but because there are so many attribute hierarchies, it’s easy to get burned by it.
Reed