Dimensional Data Operation - Drill Down / Up
About
Drilling down or up is a data navigation term along hierarchy levels of data ranging:
- from the most summarized (up)
- to the most detailed (down)
Drilling down is nothing more than adding columns from the dimension tables. Drilling up is removing them.
We can drill down or up:
- on attributes from more than one explicit hierarchy
- and with attributes that are part of no hierarchy.
Articles Related
Example
- Within the time dimension, months roll up to quarters, quarters roll up to years, and years roll up to all years.
- Within the product dimension, products roll up to subcategories, subcategories roll up to categories, and categories roll up to all products.
- Within the customer dimension, customers roll up to city. Then cities roll up to state. Then states roll up to country. Then countries roll up to sub-region. Finally, subregions roll up to region.