[ddorian43]

columnstore is supposed to not work with indices (although they have different types like zone-maps)

each column is stored separately on disk, so only the requested column-values are read from disk

This makes slow to select/update/delete a single row(oltp) since it needs to fetch multiple pages (for each column). And makes it fast to do queries regarding data in big size (olap) by doing vectorized query execution and sequential-reads on disk