Document databases are an increasingly important type of technology in the gen AI era.
A document database is a type of NoSQL database that doesn't rely on rows and columns like a traditional relational database, instead it uses the JSON (JavaScript Object Notation) format. There are multiple vendors that develop document databases including MongoDB, which now has a proprietary closed source technology. In an effort to open up the market, Microsoft began developing its own document database known as DocumentDB and made it open source in January of this year. This week, DocumentDB is moving to the Linux Foundation where it has also gained the backing of Microsoft's cloud rivals AWS and Google.
The move creates the first vendor-neutral open source alternative to MongoDB that has the potential to save enterprises money, while also eliminating database vendor lock-in. Document databases are important for AI apps for tasks such as chats, context and memory.
"AI apps are all about semi-structured data and document databases are purpose built for it," Kirill Gavrylyuk, vice president at Microsoft and DocumentDB's primary architect, told VentureBeat "But there is no open source standard engine for document databases, like what PostgreSQL is for relational databases."
Delivering the promise of open source document database at the Linux Foundation
Microsoft initially launched the open-source DocumentDB project in January of 2025.
The project was hosted within the Microsoft org on GitHub and had been generating broad industry interest over the course of the year. Having an open-source project isn't just about code or licensing, it's also about contributions and community.
"Under the Linux Foundation’s governance, DocumentDB will benefit from vendor neutrality and broader collaboration," Gavrylyuk said.
Microsoft isn't just dumping code either. Gavrylyuk emphasized that Microsoft will continue to invest heavily in the project and will continue to have strong representation in the Technical Steering Committee to help shape the vision and roadmap of the project.
"By joining the Linux Foundation, a neutral foundation, we are aiming to be more inviting to the developer community to contribute and shape the direction of the project," Gavrylyuk said. "Moreover, through the Linux Foundation, we want to provide an assurance to the developer community that this project is here to stay, open source, and will continue to move forward."
What's inside DocumentDB and why it matters for enterprise data professionals
Aside from its open-source nature, there is another critical element that makes the database particularly attractive to enterprises. Instead of being an entirely new database technology, it's based on the open-source PostgreSQL database.
PostgreSQL has emerged to become one of the most widely deployed open source databases of all time and has newfound adoption in the AI era. DocumentDB includes a PostgreSQL extension that brings first class BSON (Binary JSON) datatype support to PostgreSQL. It also integrates an extension that adds document style queries support to PostgreSQL and index management. The PostgreSQL base means that enterprises can benefit from PostgreSQL's mature ecosystem of tools, monitoring systems and backup solutions. The PostgreSQL foundation also provides ACID (Atomicity, Consistency, Isolation and Durability) compliance and proven replication capabilities that address enterprise concerns about data consistency.
DocumentDB also has a gateway that makes the database compatible with open source MongoDB drivers for any language. Gavrylyuk noted that Document DB doesn't yet have full compatibility with everything in MongoDB, but there is more work to come.
"Full compatibility with MongoDB drivers is a critical goal of the project as reflected in the Linux Foundation DocumentDB charter," he said. "This coupled with the true open source vendor neutral governance of the project will help the broader document database ecosystem thrive, benefitting everybody in the ecosystem, including MongoDB Inc."
Just to be clear, Amazon DocumentDB isn't the same thing
While Amazon is among the backers of the new Linux Foundation DocumentDB project, it actually already has its own DocumentDB database.
The Amazon DocumentDB database predates the Microsoft-led technology, having been first announced in 2019. Amazon DocumentDB recently debuted a serveless service that aims to accelerate agentic AI.
While the DocumentDB project, stewarded by Linux Foundation, has a similar name to Amazon DocumentDB, it uses different software under the hood.
"Amazon DocumentDB is a MongoDB API-compatible document database built by AWS," Rashim Gupta, Sr. Manager, Product Management at AWS, told VentureBeat. "The Linux Foundation project, on the other hand, while also being MongoDB compatible, uses an open source engine that is built as an extension on PostgreSQL. This is a different engine than the one used in Amazon DocumentDB."
Gupta noted that AWS will continue to invest in both Amazon DocumentDB and open source DocumentDB akin to how it invests in Amazon OpenSearch Service and community OpenSearch. Moving forward, he said that AWS will start contributing Amazon DocumentDB innovations to the open source project and adopt features and capabilities from the open source DocumentDB engine to its managed Amazon DocumentDB service over time.
AI workloads drive urgent need for database alternatives
The timing reflects growing enterprise demand for document databases to power AI applications.
The project already incorporates Microsoft Research's DiskANN (Disk Approximate Nearest Neighbor) vector indexing algorithms and semantic operators developed for PostgreSQL's AI capabilities.
This gives DocumentDB immediate competitive advantages for AI workloads while avoiding the licensing costs that can potentially make proprietary alternatives expensive for data-intensive applications.
“Microsoft heavily invests in open source AI contributions across the board," Gavrylyuk said. "We are investing in the AI capabilities of DocumentDB as well as the broader PostgreSQL ecosystem with priority."
What it means for enterprise data teams
For enterprises looking to reduce database vendor dependence, DocumentDB provides a strategic hedge against potential closed source proprietary technology. IT leaders should begin evaluating DocumentDB in development environments to understand migration complexity for their specific workloads.
Organizations building new AI applications have the opportunity to architect around DocumentDB from the start, avoiding potential closed-source technology lock-in entirely while gaining PostgreSQL's proven enterprise reliability and ecosystem benefits.
For enterprises looking to lead the way in AI, this news means access to cutting-edge document database capabilities without the vendor lock-in risks that have historically constrained database strategy decisions.
