whichdb
vs

Apache DataFusion vs chDB

Apache DataFusion: Extensible Rust query engine library on Apache Arrow for building databases and data systems. chDB: Embedded, in-process OLAP engine powered by ClickHouse, used mainly from Python.

key differences

  • Horizontal scaling is addon in Apache DataFusion and none in chDB.
  • Only Apache DataFusion has runs in webassembly.
  • Only chDB has geospatial, json, durable persistence, compression.

choose apache-datafusion for

  • +Building custom databases and query engines
  • +Embedded SQL in Rust services
  • +Accelerating Spark via Comet
  • +Query layer for time-series or log stores

best at · OLAP, Embedded, Lakehouse

choose chdb for

  • +Notebook analytics with ClickHouse SQL
  • +Local ETL on Parquet and CSV
  • +Testing ClickHouse queries without a server
  • +Embedding analytics in Python services

best at · OLAP, Embedded

Apache DataFusionExtensible Rust query engine library on Apache Arrow for building databases and data systems.
chDBEmbedded, in-process OLAP engine powered by ClickHouse, used mainly from Python.
overview
Primary model
Columnar / OLAP
Columnar / OLAP
Also supports
Relational
Relational, Document
Type
Embedded library
Database engine
Status
Active
Active
Developer
Apache Software Foundation
ClickHouse, Inc.
First release
2019
2023
Latest version
55.2.0 (Oct 7, 2026)
4.4.0 (Sep 11, 2026)
License
Open source (permissive)Apache License 2.0
Open source (permissive)Apache License 2.0
Free tier
✓
✓
popularity
WhichDB Score
31.6
21.1
Rank
#76
#143
GitHub stars
9.5K
2.9K
Stack Overflow questions
–
–
scale & guarantees
Comfortable data size
Medium (≤ 10 TB)
Medium (≤ 10 TB)
Horizontal scaling
Addon
None
Multi-region
None
None
ACID
None
None
Consistency
Strong
Strong
Schema
Strict
Strict
Architecture
Embedded, In memory
Embedded, In memory, 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, DataFrame API (Rust/Python), Substrait
SQL (ClickHouse dialect), Python DataFrame API
Client languages
Rust, Python
Python, Go, Rust, JavaScript, C, Bun
Best for
OLAP, Embedded, Lakehouse
OLAP, Embedded
Add more to this comparisonNot sure either fits? Try smart match

Apache DataFusion vs chDB: FAQ

What is the difference between Apache DataFusion and chDB?

Apache DataFusion: Extensible Rust query engine library on Apache Arrow for building databases and data systems. chDB: Embedded, in-process OLAP engine powered by ClickHouse, used mainly from Python. Horizontal scaling is addon in Apache DataFusion and none in chDB. Only Apache DataFusion has runs in webassembly. Only chDB has geospatial, json, durable persistence, compression.

When should I choose Apache DataFusion over chDB?

Choose Apache DataFusion for building custom databases and query engines; embedded SQL in Rust services; and accelerating Spark via Comet. Choose chDB for notebook analytics with ClickHouse SQL; local ETL on Parquet and CSV; and testing ClickHouse queries without a server.

Is Apache DataFusion or chDB more popular?

Apache DataFusion ranks #76 on the WhichDB Score (31.6/100) and chDB ranks #143 (21.1/100). Popularity is not fit: check the requirements that matter for your project.

Are Apache DataFusion and chDB open source?

Yes. Apache DataFusion is open source. License: Apache License 2.0. Yes. chDB is open source. License: Apache License 2.0.