How does PostgreSQL's scaling compare to MongoDB?

Question

I know a fair about about how amazingly scalable MongoDB is, particularly with its auto-sharding, and the ability to hot-add servers to a cluster.

However, I haven't found much data about PostgreSQL's scalability. I know it has tablespaces, much like other RDBMSs. Can it auto-grow these (like sharding)? Or is it a manual process like in SQL Server?

Does anyone know where I can get more data on this?

Answer 1

Check this presentation from Skype about their cluster. It should be able to handle a billion users.