They are useful for categorical variables. For example, is a record in the "Likes motorcycles" category? They are fast because (well, one reason) bitwise logical operations are very fast for CPUs to do.

Adtech is an example of a sector that benefits from this...they slice and dice datasets a lot to target ad campaigns and such. Being able to do that quickly is useful.

So are you saying that the data is stored in categories which allows for those types of lookups to run faster? Do you have specifics on how the design of a bitmap based database achieves this? How does it maintain these relationships? Just through 0 and 1's?

I guess it's easy for me to visualize both row and column based. Im struggling with the bitmaps concept.

Here's a good write up on some of what you are asking in their blog: https://www.featurebase.com/blog/bitmaps-making-real-time-an...

So is the thinking you run them alongside a traditional RDBMS as sort of a cache or view optimized for bitwise operations?