Examining MDX Query performance using Block Computation

In 2007 I read a very interesting blog by Mosha outlining how to Optimize a Count(Filter(.)) expression in MDX. Since then I have been particularly careful in writing MDX queries and also make sure to run it past the MDX Studio to check it. But quite frequently I come across queries on forums and blogs that take the machine and its resources for a ride and still question why aren't my queries faster when I have enough resources (disk space, RAM, paging, processors etc.). Its quite simple at times to change the query but in most occasions it is simply not possible to change the way the query returns data. Lets first get a sense of how the Analysis Services processes MDX queries. There are two major parts of the Analysis Services engine.