I want to add one more into the mix - Couchbase has something called "N1QL" ('nickel'), which is actual SQL adapted for JSON: https://www.couchbase.com/product

I want to add one more into the mix - Couchbase has something called "N1QL" ('nickel'), which is actual SQL adapted for JSON: https://www.couchbase.com/products/n1ql https://www.couchbase.com/products/n1ql It's not standalone though, you need Couchbase to use it.