I'm not arguing against this article, they seem to have made some poor choices along the road, but to say "you should never use MongoDB" is silly - even if you

I'm not arguing against this article, they seem to have made some poor choices along the road, but to say "you should never use MongoDB" is silly - even if you add "...for relational data". It has it's obvious drawbacks, of course, but MongoDB is way more than just a caching layer. Here's some social networks that are running MongoDB: http://www.mongodb.org/about/production-deployments/#social-networking http://www.mongodb.org/about/production-deployments/#social-... The list includes Foursquare. They have been running Mongo as their main storage engine for about four years now. They migrated away from MySQL, as discussed in this video: http://youtu.be/GBauy0o-Wzs?t=2m30s http://youtu.be/GBauy0o-Wzs?t=2m30s