With Cosmos DB, Microsoft wants to build one database to rule them all | TechCrunch

Also see Microsoft introduces Azure Cosmos DB, a new database with a broad money-back guarantee (GeekWire); on a related note, see Microsoft launches Azure Database for MySQL and PostgreSQL (TechCrunch)

"“What is unusual about Cosmos DB is that it provides different consistency models where the user gets a trade-off between how much consistency he gets over how much of a performance hit he takes,” Leslie Lamport, the Turing Award winner whose work underpins many of these concepts (and who also wrote the LaTeX document preparation system) and who joined Microsoft Research in 2001, told me. Cosmos DB offers three different flavors of consistency for different use cases. “Those kind of intermediary consistency guarantees sort of have been around in academic systems that people build to write papers around,” Lamport explained. Cosmos DB is among the first commercially available database systems to offer this variety of consistency models.

For Cosmos DB (and previously for DocumentDB), that means you can choose between a consistency model where reads are allowed to lag behind writes for only a certain amount of milliseconds, for example, or a model that focuses on offering consistency for a specific client session (in a Twitter-like app, for example), but where it’s not all that important that every user sees every write at the same time (or even in the exact same order)."

With Cosmos DB, Microsoft wants to build one database to rule them all | TechCrunch