Roll-up or Drill-up
The word ‘up’ in the names refers to going up in concept hierarchies.
For example, we would like to know the revenue of the whole year. However, the record of data is
Roll-up is performed by summing up everything of the column revenue. It gives us the revenue of the whole year. Monthly and quarterly roll-up is also straightforward.
wiki/data-warehouse/olap-operations.mdin other notes to connect them.
L Ma (2018). 'OLAP Operations', Datumorphism, 11 April. Available at: https://datumorphism.leima.is/wiki/data-warehouse/olap-operations/.