Comment by fridental

Ignoring the prediction that everything will be decentralized in the near future (it probably won't), how about this scenario: you want to see if the voting activity (recorded in your events) correlates with the number of times you went to the doctors in the year prior to election (as recorded in your health records). If we want to be able to run such a distributed query, we need to be sure that each node stores the data in predefined format ("tables") and that one of their services run a service that will receive the distributed query request, decide whether or not it wants to participate, and then execute the business logic of the conditions (healthevent.year > getdate() - 365), probably defined in some programming language ("SQL").