Other operators related to pivoting are rollup or drill-down.
Rollup corresponds to taking the current data object and
doing a further group-by on one of the dimensions. Thus, it is
possible to roll-up the sales data, perhaps already aggregated
on city, additionally by product. The drill-down operation is
the converse of rollup. Slice_and_dice corresponds to
reducing the dimensionality of the data, i.e., taking a
projection of the data on a subset of dimensions for selected
values of the other dimensions. For example, we can
slice_and_dice sales data for a specific product to create a
table that consists of the dimensions city and the day of sale.
The other popular operators include ranking (sorting),
selections and defining computed attributes.