As Hadi Hariri is saying: persistence ignorance has shifted:
I always mention in my presentations on CouchDB, that as much as we strived to accomplish Persistence Ignorance when working with ORM’s, when it comes to using a NoSQL solution, we can’t be ignorant about our persistence mechanism, from an architectural perspective. Depending on what we need, how we need to store the information, and how we need to query it, are factors that play an important role in the solution we opt for. This applies not only to when choosing the NoSQL solution, but also when persisting information. It is true that joins and complex queries have disappeared in Document databases, but relationships between objects in the real world have not, and based on how we need to work with this information, different techniques can should be applied.
Original title and link: Is NoSQL for me? Persistence Ignorance Has Shifted (NoSQL databases © myNoSQL)