Microsoft has made a significant move in the NoSQL database market by releasing an open-source version of its DocumentDB engine, which offers a MongoDB-compatible alternative with PostgreSQL roots. This new database engine, built on the popular PostgreSQL platform, provides developers with a standard NoSQL environment that reduces the complexity associated with migrating from one platform to another.

The DocumentDB engine, which was initially part of Microsoft's Azure Cosmos DB, has been open-sourced under a permissive MIT license. This move is seen as a strategic step by Microsoft to provide a rival to MongoDB, a popular NoSQL database, and potentially establish a standard NoSQL API and engine in the industry.

DocumentDB is built on top of PostgreSQL, which manages storage, indexing, and other key low-level operations. The engine is implemented using two components: one to add support for BSON (Binary JavaScript Object Notation) data types and one to support the DocumentDB APIs, adding CRUD operations, queries, and index management. This architecture allows developers to build on and extend a database that can support most scenarios.

The new DocumentDB engine comes with a range of features, including support for BSON data types, CRUD operations, queries, and index management. It also leverages PostgreSQL's vector index capabilities, enabling the development of complex indexes that support various query types. Additionally, DocumentDB allows developers to use PostgreSQL's standard tools and extensions to build and manage indexes.

Microsoft's decision to open-source DocumentDB is seen as a move to provide a vendor-neutral NoSQL database engine that can be used as a reference implementation for a new NoSQL standard. By allowing developers to switch protocols on top of the same underlying store, DocumentDB enables the use of familiar APIs, regardless of their source. This approach can help to establish a common standard for NoSQL databases, promoting competition based on performance, scalability, and resilience.

The first public release of DocumentDB is already available on GitHub, and developers can start building and experimenting with the engine using VS Code and Docker. The project wiki provides instructions on how to set up and use DocumentDB, including building collections, adding items, and experimenting with CRUD operations.

The DocumentDB project has already gained traction, with the latest release of the open-source FerretDB NoSQL database built using DocumentDB. The FerretDB team claims a significant performance increase of up to 20x, demonstrating the potential of DocumentDB as a foundation for NoSQL databases.

Microsoft's move to open-source DocumentDB marks a significant shift in the company's approach to software development and collaboration. The fact that the first product shipping on the standalone DocumentDB is coming from an open-source company that's not Microsoft highlights the company's willingness to engage with the open-source community and promote innovation.

As DocumentDB continues to evolve, it will be interesting to see how the community responds to this new NoSQL database engine. With Microsoft's backing and the potential for a new NoSQL standard, DocumentDB is definitely a project to keep an eye on in the coming months.