OLAP operations are a set of possible actions that a report can get done with the respective reactions and the effects it causes. Let’s talk about the main one of them:
Drill Down and Slice & Dice
Drill Down: promote a more detailed view of a dataset, going deeper-in the data dimensions. The more you add characteristics in a report, the more drill-down you are doing.
Roll Up: present grouped data, with fewer details and more aggregation. The more characteristics you remove from a report, the more roll-up you are doing.
Slice & Dice
Slice: would be the act to filter one specific dimension characteristic and show all data inside it.
Dice: would be the serie of filter actions from different characteristics, getting a very specific figure.
it’s possible to build a drill-across report when the data merge equality at some specific level, promoting only one view from different datasets.
Defined as the connection from a report to another, with some information relation, making possible the navigation or interaction between them.
It’s basically the change of perspective of the same dataset. An easy example to see it’s when we have an excel data file and want to invert the position of a column by rows.
It’s good to keep in mind that these operations are firstly related to the concept and then secondary to tools. That means it’s important to understand for example, what is behind for the term “drill-down” and then build or execute that functionality in the tool you are working, like Power BI, Qlick view, Tableu, Lumira, etc. Each one will offer you different technical possibilities in your very specific way, but at the end of the day, the functionality will be “drill-down”.