![rotate and roll level 14 rotate and roll level 14](https://i.ytimg.com/vi/fyDxS4Rtiac/hqdefault.jpg)
It navigates the data from less detailed data to highly detailed data. When drill-down is performed, one or more dimensions from the data cube are added. On drilling down, the time dimension is descended from the level of quarter to the level of month. Initially the concept hierarchy was "day < month < quarter < year." The following diagram illustrates how drill-down works −ĭrill-down is performed by stepping down a concept hierarchy for the dimension time.
![rotate and roll level 14 rotate and roll level 14](https://media.springernature.com/lw685/springer-static/image/art%3A10.1007%2Fs13349-020-00400-9/MediaObjects/13349_2020_400_Fig2_HTML.png)
![rotate and roll level 14 rotate and roll level 14](https://www.simplyrecipes.com/thmb/_UJtKqsy6PkRl9SNTT5OobHb-WQ=/3000x2003/filters:no_upscale():max_bytes(150000):strip_icc()/Simply-Recipes-Brazo-Gitano-LEAD-1-9faf2695368a40aca832cb1ae070e78d.jpg)
The aggregations are stored separately in MOLAP store. HOLAP servers allows to store the large data volumes of detailed information. It offers higher scalability of ROLAP and faster computation of MOLAP. Hybrid OLAP is a combination of both ROLAP and MOLAP. Therefore, many MOLAP server use two levels of data storage representation to handle dense and sparse data sets. With multidimensional data stores, the storage utilization may be low if the data set is sparse. MOLAP uses array-based multidimensional storage engines for multidimensional views of data.