ToroDB is a document oriented, Mongo-compatible, open-source database built on top of PostgreSQL.
Why all NoSQL databases are doing everything from scratch? Concurrency, durability, journaling... all those are quite tough goals to achieve. Aren't RDBMs good enough?
We think they are, specially PostgreSQL. So we built ToroDB, a new “NoSQL” database, that speaks JSON, and uses PostgreSQL as the “storage layer”. ToroDB doesn't use PostgreSQL's fantastic jsonb type; it instead offers a novel approach storing data relationally. JSON documents are split into parts, each of which is stored in a relation (table). This has several advantages, which will be outlined during the course of the talk.
ToroDB implements the MongoDB protocol, and is thus compatible with MongoDB applications. This means it supports the advanced MongoDB query language, and MongoDB language updates. And it's all open source and running on top of PostgreSQL :)