Getting the summary
The advantages of a multi-dimensional cube are that the data is pre-aggregated and that there is a lot of metadata that we can use for calculations. There is no need to re-aggregate data at the query time, and we have pre-defined calculation formulas in the cube. Not to mention that all metrics are formatted in the cube. Reporting tools should take advantage of this instead of reinventing the wheel.
It is always a good idea to reply on MDX queries to get the correct aggregation no matter what tool you use, so that the need to aggregate in the reporting tool is eliminated.
Visual totals are totals at the end of a column or row that add up all of the items visible in the column or row. By default, when placing the All
member in the query, totals including both visual and non-visual items will be displayed for most pivot tables. For MDX queries that do not show all the items, this default behavior is misleading because we only want the totals to include the visual items.