I have an Oracle 12c database with many schemas, each schema belongs to a specific application.
I want to produce a query that shows me which schemas are the busiest in terms of read/write activity / IO etc.
I know that I can use the DBA_TAB_MODIFICATIONS table to get modifications since the last stats update, per table.
I've been told that the DBA_HIST objects will be able to give me more information but there's a lot of data there and I don't really know how to get the best out of it for this purpose.
Any help would be appreciated.