The Best of Both Worlds Schemaless database are a joy to use because they make it easy to iterate on your app, especially early on. And to be honest, the relational model isn't always the best fit for real-world evolving and messy data. On the other hand, relational databases are proven, robust, and powerful. Also, over time as your data model stabilizes, the lack of well-defined schemas becomes painful. How are we supposed to pick one or the other? Simple: pick both. Fortunately recent advances in Postgres allow for a hybrid approach that we've been using at Heroku. The hstore datatype gives you key/value in a single column, and PLV8 enables JavaScript and JSON in Postgres. These and others in turn make Postgres the best document database in the world. We will explore the power of hstore and PLV8, explain how to use them in your project today, and examine their role in the future of data.