Ah sorry, my bad. You are correct that you can fire off many random access operations in parallel and get good throughput that way.
The problem is that this is not possible when the next IO request depends on the result of a previous one, like in a database where you must first read the index to know the location of the row data itself.
The problem is that this is not possible when the next IO request depends on the result of a previous one, like in a database where you must first read the index to know the location of the row data itself.