Make this good enough and you could very well cut into a huge chunk of Firebase's business model. I'd seriously love to have query subscriptions, especially if

Make this good enough and you could very well cut into a huge chunk of Firebase's business model. I'd seriously love to have query subscriptions, especially if the library is robust enough for use on mobile. Ine large differentiator of Firebase's DB offerings is the subscription functionality, mobile and web, but using that means buying into NoSQL. A proper subscribable SQL database would be amazing. Of course the conflict resolution on writes, and the local caching is another key benefit Firebase offers. Not sure how that could be done with a real relational DB!