whichdb
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chDB vs ClickHouse

chDB: Embedded, in-process OLAP engine powered by ClickHouse, used mainly from Python. ClickHouse: Open-source columnar OLAP database known for very fast aggregations over billions of rows.

key differences

  • ClickHouse is built for larger datasets (Multi-PB) than chDB (≤ 10 TB).
  • Horizontal scaling is none in chDB and native in ClickHouse.
  • Transactions: chDB offers none ACID; ClickHouse offers limited.
  • Only chDB has in-memory.
  • Only ClickHouse has secondary indexes, full-text search, vector search, materialized views, ttl / expiry.
  • ClickHouse has a serverless option; chDB does not.
  • chDB can run embedded in your application process.

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

choose clickhouse for

  • +Product and web analytics
  • +Log and observability backends
  • +Real-time dashboards over event streams
  • +Time-series and IoT metrics at scale

best at · Real-time analytics, OLAP, Observability

chDBEmbedded, in-process OLAP engine powered by ClickHouse, used mainly from Python.
ClickHouseOpen-source columnar OLAP database known for very fast aggregations over billions of rows.
overview
Primary model
Columnar / OLAP
Columnar / OLAP
Also supports
Relational, Document
Relational, Document, Vector, Time-Series
Type
Database engine
Database engine
Status
Active
Active
Developer
ClickHouse, Inc.
ClickHouse, Inc.
First release
2023
2016
Latest version
4.4.0 (Sep 11, 2026)
26.10.2.103 (Oct 24, 2026)
License
Open source (permissive)Apache License 2.0
Open source (permissive)Apache License 2.0
Free tier
✓
✓
popularity
WhichDB Score
21.1
69.8
Rank
#143
#10
GitHub stars
2.9K
50.6K
Stack Overflow questions
–
2.2K
scale & guarantees
Comfortable data size
Medium (≤ 10 TB)
Massive (Multi-PB)
Horizontal scaling
None
Native
Multi-region
None
Read replicas
ACID
None
Limited
Consistency
Strong
Eventual
Schema
Strict
Strict
Architecture
Embedded, In memory, Single node
Distributed, Shared storage, Single node, Client server
deployment
Self-hosted
✓
✓
Vendor-managed cloud
—
✓
Serverless
—
✓
Embedded
✓
—
Edge
—
—
Clouds
–
AWS, Google Cloud, Azure, Alibaba Cloud, Tencent Cloud, Aiven
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 (ClickHouse dialect), Python DataFrame API
SQL (ClickHouse dialect), PRQL, KQL (experimental)
Client languages
Python, Go, Rust, JavaScript, C, Bun
Python, Go, Java, JavaScript, Rust, C++, C#
Best for
OLAP, Embedded
Real-time analytics, OLAP, Observability, Warehouse
Add more to this comparisonNot sure either fits? Try smart match

chDB vs ClickHouse: FAQ

What is the difference between chDB and ClickHouse?

chDB: Embedded, in-process OLAP engine powered by ClickHouse, used mainly from Python. ClickHouse: Open-source columnar OLAP database known for very fast aggregations over billions of rows. ClickHouse is built for larger datasets (Multi-PB) than chDB (≤ 10 TB). Horizontal scaling is none in chDB and native in ClickHouse. Transactions: chDB offers none ACID; ClickHouse offers limited.

When should I choose chDB over ClickHouse?

Choose chDB for notebook analytics with ClickHouse SQL; local ETL on Parquet and CSV; and testing ClickHouse queries without a server. Choose ClickHouse for product and web analytics; log and observability backends; and real-time dashboards over event streams.

Is chDB or ClickHouse more popular?

ClickHouse ranks #10 on the WhichDB Score (69.8/100) and chDB ranks #143 (21.1/100). Popularity is not fit: check the requirements that matter for your project.

Are chDB and ClickHouse open source?

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