Surprised by the downvote. It is an open source solution that does exactly what the parent comment was asking (not having to think about how to map json to a relational database). I don't see a problem mentioning some software (again: open source) as a viable solution to that problem.

It's trendy on HN to like SQL databases and bash MongoDB.

Really? I thought it was the other way around.

Try not to make generalizations of a rather diverse crowd.

I know. But there was no MongoDB bashing -- at least in the comment ;)