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ClickHouse vs Mondrian

ClickHouse: Open-source columnar OLAP database known for very fast aggregations over billions of rows. Mondrian: Java ROLAP engine that answers MDX queries by generating SQL against your relational warehouse.

key differences

  • ClickHouse is primarily a columnar / OLAP database; Mondrian is relational.
  • Licensing: ClickHouse is open source (permissive) (Apache License 2.0); Mondrian is source-available (Business Source License 1.1 (since 10.3; older releases EPL)).
  • ClickHouse is built for larger datasets (Multi-PB) than Mondrian (≤ 10 TB).
  • Horizontal scaling is native in ClickHouse and none in Mondrian.
  • Transactions: ClickHouse offers limited ACID; Mondrian offers none.
  • Only ClickHouse has secondary indexes, full-text search, vector search, geospatial, json.
  • ClickHouse has a serverless option; Mondrian does not.
  • Mondrian can run embedded in your application process.

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

choose mondrian for

  • +Pivot-style analytics over a star schema in PostgreSQL, MySQL or a warehouse
  • +Embedding OLAP cubes in Java BI applications
  • +Pentaho Business Analytics deployments

best at · OLAP, Warehouse

ClickHouseOpen-source columnar OLAP database known for very fast aggregations over billions of rows.
MondrianJava ROLAP engine that answers MDX queries by generating SQL against your relational warehouse.
overview
Primary model
Columnar / OLAP
Relational
Also supports
Relational, Document, Vector, Time-Series
–
Type
Database engine
Database engine
Status
Active
Active
Developer
ClickHouse, Inc.
Pentaho
First release
2016
2002
Latest version
26.10.2.103 (Oct 24, 2026)
–
License
Open source (permissive)Apache License 2.0
Source-availableBusiness Source License 1.1 (since 10.3; older releases EPL)
Free tier
✓
✓
popularity
WhichDB Score
69.8
12.4
Rank
#10
#267
GitHub stars
50.6K
1.2K
Stack Overflow questions
2.2K
477
scale & guarantees
Comfortable data size
Massive (Multi-PB)
Medium (≤ 10 TB)
Horizontal scaling
Native
None
Multi-region
Read replicas
None
ACID
Limited
None
Consistency
Eventual
Eventual
Schema
Strict
Strict
Architecture
Distributed, Shared storage, Single node, Client server
Embedded, 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), PRQL, KQL (experimental)
MDX
Client languages
Python, Go, Java, JavaScript, Rust, C++, C#
Java
Best for
Real-time analytics, OLAP, Observability, Warehouse
OLAP, Warehouse
Add more to this comparisonNot sure either fits? Try smart match

ClickHouse vs Mondrian: FAQ

What is the difference between ClickHouse and Mondrian?

ClickHouse: Open-source columnar OLAP database known for very fast aggregations over billions of rows. Mondrian: Java ROLAP engine that answers MDX queries by generating SQL against your relational warehouse. ClickHouse is primarily a columnar / OLAP database; Mondrian is relational. Licensing: ClickHouse is open source (permissive) (Apache License 2.0); Mondrian is source-available (Business Source License 1.1 (since 10.3; older releases EPL)). ClickHouse is built for larger datasets (Multi-PB) than Mondrian (≤ 10 TB).

When should I choose ClickHouse over Mondrian?

Choose ClickHouse for product and web analytics; log and observability backends; and real-time dashboards over event streams. Choose Mondrian for pivot-style analytics over a star schema in PostgreSQL, MySQL or a warehouse; embedding OLAP cubes in Java BI applications; and pentaho Business Analytics deployments.

Is ClickHouse or Mondrian more popular?

ClickHouse ranks #10 on the WhichDB Score (69.8/100) and Mondrian ranks #267 (12.4/100). Popularity is not fit: check the requirements that matter for your project.

Are ClickHouse and Mondrian open source?

Yes. ClickHouse is open source. License: Apache License 2.0. Not in the OSI sense. Mondrian is source-available: you can read the code, but the license restricts some uses, typically offering it as a competing managed service. License: Business Source License 1.1 (since 10.3; older releases EPL).