OLAP Operations and Data Cube Aggregation Previous Year Questions (PYQs) for GATE DA: 2+ Solved Questions with Step-by-Step Solutions

Consider a fact table in an OLAP application: $Facts(D1,D2,val)$, where $D1$ and $D2$ are its dimension attributes and $val$ is a dependent attribute. Suppose attribute $D1$ takes $3$ values and $D2$ takes $2$ values, and all combinations of these values are present in the table $Facts$. How many tuples are there in the result of the following query?

SELECT D1, D2, sum(val)
FROM Facts
GROUP BY CUBE (D1, D2);

Consider that the visualization of a 3-dimensional data cube is showing Sales Quantity for each combination of the attributes Product Type, Month and Country.
From this, if we want to further visualize the Sales Quantity for each combination of Product Type, Month and State, which of the following OLAP operations should be performed?