If all you have is a hummer everything look like a nail: when Hadoop first appeared there was almost no other open source systems to process 'big data' and it w

If all you have is a hummer everything look like a nail: when Hadoop first appeared there was almost no other open source systems to process 'big data' and it was widely adopted. Now there are many options to choose from. We don't have to use map-reduce for every task which could be solved using map-redude. E. g. for some tasks a columnar store, like ClickHouse is a better fit.