You should use raster indexes for tables with fairly static low power values (a small number of different values that don't change very often). To use a bitmap, there must be less than 1%, and if less than 0.1%, then this is most likely the best option. There is a high overhead for maintaining raster image indices compared to the b-tree, so they are best suited for data that rarely changes, although the suitability in this case is determined by the application, where it is possible that the data changes and reporting are not parallel, and therefore you put on Do not pay attention to extra effort.
To give a simple example: in the employee table, if you specified gender, title, department, age, and employee #, you would choose a bitmap for gender and name, and possibly for department, but probably not for age and definitely not for employee numbers