DocumentDB (open-source, PostgreSQL-based)
activeby DocumentDB project (Linux Foundation; originated at Microsoft) · since 2025 · also known as DocumentDB, pg_documentdb, DocumentDB Linux Foundation
MIT-licensed, MongoDB-compatible document engine built as PostgreSQL extensions, run by the Linux Foundation.
Overview
DocumentDB is an open-source document database that stores native BSON inside PostgreSQL through the pg_documentdb_core and pg_documentdb extensions, with a Rust gateway that speaks the MongoDB wire protocol. Microsoft open-sourced it in January 2025 as the engine behind Azure DocumentDB, then donated it to the Linux Foundation in August 2025; its steering committee now includes Microsoft, AWS, Rippling and Yugabyte. Version 1.0, the first GA release, shipped on 19 October 2026 alongside a 1.0 Kubernetes operator. It is the most credible permissively licensed path to MongoDB-compatible storage, and it inherits PostgreSQL's durability and tooling.
Strengths & trade-offs
Strengths
- +MIT license with vendor-neutral Linux Foundation governance
- +Works with existing MongoDB drivers and tools such as mongosh and Compass
- +Runs on stock PostgreSQL 15-18, so backups, replication and monitoring are familiar
- +Vector search via pgvector and text indexes built in
- +Backed by several cloud vendors, which makes it a likely common standard
Trade-offs
- −Very young as a GA product (1.0 in October 2026); compatibility gaps remain
- −No open-source horizontal sharding yet
- −Change streams and some admin commands are incomplete
- −Performance tuning means understanding both PostgreSQL internals and MongoDB semantics
Great for
- +Self-hosted MongoDB-compatible database without SSPL
- +Migrating MongoDB apps onto PostgreSQL infrastructure
- +Document plus vector storage for RAG on Kubernetes
- +Local development matching Azure DocumentDB
Think twice for
- −Multi-terabyte write-heavy workloads needing sharding
- −Apps relying on the newest MongoDB-specific features
Capabilities
Native or official first-party support · 11 of 25 tracked
Scale & consistency
- Comfortable data size
- Medium · ≤ 10 TB
- Horizontal scaling
- None
- Multi-region
- Read replicas
- Transactions
- Full ACID
- Consistency
- Strong
- Schema
- Schemaless
- Architecture
- Primary replica, Client server
- Query languages
- MongoDB Query API (MQL), Aggregation pipeline, SQL (via PostgreSQL)
Scales like a single PostgreSQL primary with streaming replicas; the operator handles HA and cross-cluster replication. Transparent sharding exists only in the Azure service today.
Deployment
Ecosystem
Alternatives to DocumentDB (open-source, PostgreSQL-based)
The default document database: flexible BSON documents, rich queries and built-in sharding.
documentdb-postgres vs mongodb →Apache-licensed MongoDB-protocol proxy that stores data in PostgreSQL with the DocumentDB extension.
documentdb-postgres vs ferretdb →Microsoft's managed MongoDB-compatible service, built on the open-source DocumentDB engine.
documentdb-postgres vs azure-documentdb →AWS's managed MongoDB-API database on a proprietary, Aurora-style storage layer.
documentdb-postgres vs amazon-documentdb →The extensible, standards-first open-source relational database.
documentdb-postgres vs postgresql →Drop-in MongoDB Community build with enterprise features like encryption, LDAP and hot backup.
documentdb-postgres vs percona-server-mongodb →DocumentDB (open-source, PostgreSQL-based) FAQ
What is DocumentDB (open-source, PostgreSQL-based)?
DocumentDB (open-source, PostgreSQL-based) is a document database by DocumentDB project (Linux Foundation; originated at Microsoft), first released in 2025. DocumentDB is an open-source document database that stores native BSON inside PostgreSQL through the pg_documentdb_core and pg_documentdb extensions, with a Rust gateway that speaks the MongoDB wire protocol. Microsoft open-sourced it in January 2025 as the engine behind Azure DocumentDB, then donated it to the Linux Foundation in August 2025; its steering committee now includes Microsoft, AWS, Rippling and Yugabyte. Version 1.0, the first GA release, shipped on 19 October 2026 alongside a 1.0 Kubernetes operator. It is the most credible permissively licensed path to MongoDB-compatible storage, and it inherits PostgreSQL's durability and tooling.
Is DocumentDB (open-source, PostgreSQL-based) open source?
Yes. DocumentDB (open-source, PostgreSQL-based) is open source. License: MIT License.
Does DocumentDB (open-source, PostgreSQL-based) support ACID transactions?
Yes. DocumentDB (open-source, PostgreSQL-based) supports full ACID transactions, with strong consistency.
Does DocumentDB (open-source, PostgreSQL-based) scale horizontally?
DocumentDB (open-source, PostgreSQL-based) does not scale horizontally; it runs on a single node, so you scale it up rather than out. It is comfortable at medium scale (≤ 10 TB). It supports cross-region read replicas.
How can I run DocumentDB (open-source, PostgreSQL-based)?
You can self-host it. Managed offerings include Azure DocumentDB.
What is DocumentDB (open-source, PostgreSQL-based) best for?
DocumentDB (open-source, PostgreSQL-based) is a strong fit for self-hosted MongoDB-compatible database without SSPL, migrating MongoDB apps onto PostgreSQL infrastructure and document plus vector storage for RAG on Kubernetes. Think twice for multi-terabyte write-heavy workloads needing sharding.
What are the best alternatives to DocumentDB (open-source, PostgreSQL-based)?
Common alternatives to DocumentDB (open-source, PostgreSQL-based) include MongoDB, FerretDB, Azure DocumentDB, Amazon DocumentDB and PostgreSQL. The right choice depends on your workload, scale and hosting; WhichDB's smart match ranks them against your requirements.
How popular is DocumentDB (open-source, PostgreSQL-based)?
DocumentDB (open-source, PostgreSQL-based) ranks #386 of 844 databases on the WhichDB Score (5.4/100), and #35 among document databases. The score combines public adoption signals such as package downloads, GitHub activity, job posts and developer discussion.