Cube structure optimization for MDX query performance in Analysis Services 2005 SP2: Tips for Parent Child Hierarchies usage

Note: The below findings have been found on the PC hierarchies. The same may or may not be applicable to level based hierarchies since I have not tested them. I need to convert the same PC hierarchies to level based ones and then retest to find out if the similar issues exists with them too.

The bottom line of this blog, Analysis Servies 2005 does not handle rollup operators and custom members on Parent Child hierarchies properly leading to significant MDX query performance bottlenecks.