whichdb
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DuckDB vs H2 Database

DuckDB: In-process columnar SQL database: the SQLite of analytics, running inside your app or notebook. H2 Database: Fast pure-Java SQL engine for embedded, in-memory and test databases, with compatibility modes.

key differences

  • DuckDB is primarily a columnar / OLAP database; H2 Database is relational.
  • Licensing: DuckDB is open source (permissive) (MIT License); H2 Database is open source (copyleft) (MPL 2.0 or EPL 1.0 (dual)).
  • DuckDB is built for larger datasets (≤ 10 TB) than H2 Database (≤ 100 GB).
  • Only DuckDB has vector search, columnar storage, runs in webassembly.
  • Only H2 Database has triggers, stored procedures, role-based access.

choose duckdb for

  • +Local data analysis in notebooks
  • +ETL and data-engineering pipelines on files
  • +Embedded analytics inside applications
  • +Querying data lakes on S3 without a cluster

best at · OLAP, Embedded, Lakehouse

choose h2 for

  • +Integration tests for Spring/JPA applications
  • +Embedded storage in Java desktop tools
  • +Prototyping before choosing a production database
  • +In-memory scratch databases in batch jobs

best at · Embedded, OLTP, Coordination

DuckDBIn-process columnar SQL database: the SQLite of analytics, running inside your app or notebook.
H2 DatabaseFast pure-Java SQL engine for embedded, in-memory and test databases, with compatibility modes.
overview
Primary model
Columnar / OLAP
Relational
Also supports
Relational, Document, Spatial, Vector
Spatial
Type
Database engine
Database engine
Status
Active
Active
Developer
DuckDB Foundation / DuckDB Labs
H2 Group (Thomas Mueller, Evgenij Ryazanov and contributors)
First release
2019
2005
Latest version
2.0.0 (Oct 21, 2026)
2.5.252 (Sep 24, 2026)
License
Open source (permissive)MIT License
Open source (copyleft)MPL 2.0 or EPL 1.0 (dual)
Free tier
✓
✓
popularity
WhichDB Score
63.7
23.5
Rank
#13
#128
GitHub stars
42.6K
4.6K
Stack Overflow questions
501
5.1K
scale & guarantees
Comfortable data size
Medium (≤ 10 TB)
Small (≤ 100 GB)
Horizontal scaling
None
None
Multi-region
None
None
ACID
Full
Full
Consistency
Strong
Strong
Schema
Strict
Strict
Architecture
Embedded, Single node, In memory
Embedded, In memory, Client server, Single node
deployment
Self-hosted
✓
✓
Vendor-managed cloud
—
—
Serverless
—
—
Embedded
✓
✓
Edge
—
—
Clouds
–
–
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
SQL (PostgreSQL-like dialect)
SQL
Client languages
Python, R, Java, JavaScript, Go, Rust, C, Swift
Java
Best for
OLAP, Embedded, Lakehouse, Warehouse
Embedded, OLTP, Coordination
Add more to this comparisonNot sure either fits? Try smart match

DuckDB vs H2 Database: FAQ

What is the difference between DuckDB and H2 Database?

DuckDB: In-process columnar SQL database: the SQLite of analytics, running inside your app or notebook. H2 Database: Fast pure-Java SQL engine for embedded, in-memory and test databases, with compatibility modes. DuckDB is primarily a columnar / OLAP database; H2 Database is relational. Licensing: DuckDB is open source (permissive) (MIT License); H2 Database is open source (copyleft) (MPL 2.0 or EPL 1.0 (dual)). DuckDB is built for larger datasets (≤ 10 TB) than H2 Database (≤ 100 GB).

When should I choose DuckDB over H2 Database?

Choose DuckDB for local data analysis in notebooks; ETL and data-engineering pipelines on files; and embedded analytics inside applications. Choose H2 Database for integration tests for Spring/JPA applications, embedded storage in Java desktop tools and prototyping before choosing a production database.

Is DuckDB or H2 Database more popular?

DuckDB ranks #13 on the WhichDB Score (63.7/100) and H2 Database ranks #128 (23.5/100). Popularity is not fit: check the requirements that matter for your project.

Are DuckDB and H2 Database open source?

Yes. DuckDB is open source. License: MIT License. Yes. H2 Database is open source. License: MPL 2.0 or EPL 1.0 (dual).