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Datahike vs Datomic

Datahike: Open-source, durable Datalog database for Clojure with Datomic-style immutable history. Datomic: Immutable Datalog database from Nubank where every fact is timestamped and queries run in the app process.

key differences

  • Licensing: Datahike is open source (copyleft) (Eclipse Public License 1.0); Datomic is open source (permissive) (Apache-2.0 (binaries only; source not published)).
  • Datomic is built for larger datasets (≤ 10 TB) than Datahike (≤ 100 GB).
  • Only Datahike has in-memory.
  • Only Datomic has full-text search, change data capture.

choose datahike for

  • +Clojure apps wanting Datalog and history without Datomic
  • +Knowledge graphs and research data with provenance
  • +Embedded databases in ClojureScript apps

best at · OLTP, Knowledge graph, Embedded

choose datomic for

  • +Financial and banking domain models needing auditability
  • +Systems that must answer what was known at a given time
  • +Complex domain graphs in Clojure services

best at · OLTP, Event sourcing, Ledger

DatahikeOpen-source, durable Datalog database for Clojure with Datomic-style immutable history.
DatomicImmutable Datalog database from Nubank where every fact is timestamped and queries run in the app process.
overview
Primary model
Relational
Relational
Also supports
Graph
Graph
Type
Database engine
Database engine
Status
Active
Active
Developer
replikativ (Christian Weilbach and contributors)
Nubank (Cognitect)
First release
2018
2012
Latest version
0.8.1913 (Oct 26, 2026)
1.0.7745 (Oct 16, 2026)
License
Open source (copyleft)Eclipse Public License 1.0
Open source (permissive)Apache-2.0 (binaries only; source not published)
Free tier
✓
✓
popularity
WhichDB Score
5.8
14.9
Rank
#374
#225
GitHub stars
1.9K
–
Stack Overflow questions
–
436
scale & guarantees
Comfortable data size
Small (≤ 100 GB)
Medium (≤ 10 TB)
Horizontal scaling
None
None
Multi-region
None
None
ACID
Full
Full
Consistency
Strong
Strong
Schema
Flexible
Flexible
Architecture
Embedded, Client server
Distributed, Shared storage
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
Datalog, Pull API
Datalog, Pull API
Client languages
Clojure, ClojureScript, Java
Clojure, Java
Best for
OLTP, Knowledge graph, Embedded
OLTP, Event sourcing, Ledger, Knowledge graph
Add more to this comparisonNot sure either fits? Try smart match

Datahike vs Datomic: FAQ

What is the difference between Datahike and Datomic?

Datahike: Open-source, durable Datalog database for Clojure with Datomic-style immutable history. Datomic: Immutable Datalog database from Nubank where every fact is timestamped and queries run in the app process. Licensing: Datahike is open source (copyleft) (Eclipse Public License 1.0); Datomic is open source (permissive) (Apache-2.0 (binaries only; source not published)). Datomic is built for larger datasets (≤ 10 TB) than Datahike (≤ 100 GB). Only Datahike has in-memory.

When should I choose Datahike over Datomic?

Choose Datahike for clojure apps wanting Datalog and history without Datomic; knowledge graphs and research data with provenance; and embedded databases in ClojureScript apps. Choose Datomic for financial and banking domain models needing auditability; systems that must answer what was known at a given time; and complex domain graphs in Clojure services.

Is Datahike or Datomic more popular?

Datomic ranks #225 on the WhichDB Score (14.9/100) and Datahike ranks #374 (5.8/100). Popularity is not fit: check the requirements that matter for your project.

Are Datahike and Datomic open source?

Yes. Datahike is open source. License: Eclipse Public License 1.0. Yes. Datomic is open source. License: Apache-2.0 (binaries only; source not published).