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Amazon DocumentDB vs DocumentDB (open-source, PostgreSQL-based)

Amazon DocumentDB: AWS's managed MongoDB-API database on a proprietary, Aurora-style storage layer. DocumentDB (open-source, PostgreSQL-based): MIT-licensed, MongoDB-compatible document engine built as PostgreSQL extensions, run by the Linux Foundation.

key differences

  • Licensing: Amazon DocumentDB is proprietary (Proprietary AWS service); DocumentDB (open-source, PostgreSQL-based) is open source (permissive) (MIT License).
  • Amazon DocumentDB is built for larger datasets (≤ 1 PB) than DocumentDB (open-source, PostgreSQL-based) (≤ 10 TB).
  • Horizontal scaling is native in Amazon DocumentDB and none in DocumentDB (open-source, PostgreSQL-based).
  • Only Amazon DocumentDB has change data capture, compression, encryption at rest.
  • Amazon DocumentDB has a serverless option; DocumentDB (open-source, PostgreSQL-based) does not.

choose amazon-documentdb for

  • +Lift-and-shift of MongoDB apps already running on AWS
  • +Catalogs, profiles and content stores for AWS-native services
  • +Vector search alongside JSON documents in AWS

best at · OLTP, Content, Metadata

choose documentdb-postgres 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

best at · OLTP, Content, Vector search

Amazon DocumentDBAWS's managed MongoDB-API database on a proprietary, Aurora-style storage layer.
DocumentDB (open-source, PostgreSQL-based)MIT-licensed, MongoDB-compatible document engine built as PostgreSQL extensions, run by the Linux Foundation.
overview
Primary model
Document
Document
Also supports
Vector, Spatial
Vector, Spatial
Type
Managed service
Database engine
Status
Active
Active
Developer
Amazon Web Services
DocumentDB project (Linux Foundation; originated at Microsoft)
First release
2019
2025
Latest version
8.0 (Nov 11, 2025)
1.0 (Oct 19, 2026)
License
ProprietaryProprietary AWS service
Open source (permissive)MIT License
Free tier
—
✓
popularity
WhichDB Score
15.7
5.4
Rank
#204
#386
GitHub stars
–
3.5K
Stack Overflow questions
462
–
scale & guarantees
Comfortable data size
Large (≤ 1 PB)
Medium (≤ 10 TB)
Horizontal scaling
Native
None
Multi-region
Read replicas
Read replicas
ACID
Full
Full
Consistency
Strong, Eventual
Strong
Schema
Flexible
Schemaless
Architecture
Shared storage, Primary replica, Serverless
Primary replica, Client server
deployment
Self-hosted
—
✓
Vendor-managed cloud
✓
—
Serverless
✓
—
Embedded
—
—
Edge
—
—
Clouds
AWS
–
capabilities
Transactions
✓
✓
Joins
✓
✓
Secondary indexes
✓
✓
Full-text search
✓
✓
Vector search
✓
✓
Geospatial
✓
✓
JSON
✓
✓
Change data capture
✓
—
Triggers
—
—
Stored procedures
—
—
Materialized views
—
—
TTL / expiry
✓
✓
Pub/Sub
—
—
Columnar storage
—
—
In-memory
—
—
Durable persistence
✓
✓
Compression
✓
—
Encryption at rest
✓
—
Role-based access
✓
✓
Time travel
—
—
Branching
—
—
Online schema changes
✓
✓
Streaming ingest
—
—
Offline sync
—
—
Runs in WebAssembly
—
—
interfaces
Query languages
MongoDB Query API (MQL), Aggregation pipeline
MongoDB Query API (MQL), Aggregation pipeline, SQL (via PostgreSQL)
Client languages
Java, Python, JavaScript, Go, C#, PHP, Ruby
Java, Python, JavaScript, Go, C#, Rust
Best for
OLTP, Content, Metadata, Vector search
OLTP, Content, Vector search, RAG
Add more to this comparisonNot sure either fits? Try smart match

Amazon DocumentDB vs DocumentDB (open-source, PostgreSQL-based): FAQ

What is the difference between Amazon DocumentDB and DocumentDB (open-source, PostgreSQL-based)?

Amazon DocumentDB: AWS's managed MongoDB-API database on a proprietary, Aurora-style storage layer. DocumentDB (open-source, PostgreSQL-based): MIT-licensed, MongoDB-compatible document engine built as PostgreSQL extensions, run by the Linux Foundation. Licensing: Amazon DocumentDB is proprietary (Proprietary AWS service); DocumentDB (open-source, PostgreSQL-based) is open source (permissive) (MIT License). Amazon DocumentDB is built for larger datasets (≤ 1 PB) than DocumentDB (open-source, PostgreSQL-based) (≤ 10 TB). Horizontal scaling is native in Amazon DocumentDB and none in DocumentDB (open-source, PostgreSQL-based).

When should I choose Amazon DocumentDB over DocumentDB (open-source, PostgreSQL-based)?

Choose Amazon DocumentDB for lift-and-shift of MongoDB apps already running on AWS; catalogs, profiles and content stores for AWS-native services; and vector search alongside JSON documents in AWS. Choose DocumentDB (open-source, PostgreSQL-based) for self-hosted MongoDB-compatible database without SSPL, migrating MongoDB apps onto PostgreSQL infrastructure and document plus vector storage for RAG on Kubernetes.

Is Amazon DocumentDB or DocumentDB (open-source, PostgreSQL-based) more popular?

Amazon DocumentDB ranks #204 on the WhichDB Score (15.7/100) and DocumentDB (open-source, PostgreSQL-based) ranks #386 (5.4/100). Popularity is not fit: check the requirements that matter for your project.

Are Amazon DocumentDB and DocumentDB (open-source, PostgreSQL-based) open source?

No. Amazon DocumentDB is proprietary, closed-source software. Yes. DocumentDB (open-source, PostgreSQL-based) is open source. License: MIT License.