Ontop vs Stardog

Both are rdf databases queried with SPARQL. Ontop (2009, Apache-2.0, Java) ranks #18 this month; Stardog (2011, Proprietary, Java) ranks #23.

Attribute Ontop #18 ▼1 Strong Stardog #23 ▲3 Strong
At a glance
Rank #18#23
Score 59.057.4
GitHub stars 938
Popularity 69.954.6
Activity 50.899.1
Community 74.035.3
Research 53.449.6
Fundamentals
Description A Virtual Knowledge Graph system that exposes relational databases as RDF knowledge graphs, translating SPARQL queries into SQL without moving data. Uses R2RML mappings and lightweight ontologies.An RDF-based knowledge graph database with OWL 2 reasoning and property graph extensions. Includes Voicebox, an OpenAI-compatible natural language query interface via LLM integration.
Vendor OntopicStardog Union
Model RDFRDF
Kind query-enginedatabase
Category EstablishedEnterprise
First released 20092011
Status activeactive
License Apache-2.0Proprietary
Written in JavaJava
Query languages SPARQLSPARQL, SQL, GraphQL
gdotv support noyes

Feature scores — not surveyed for Ontop

Feature OntopStardog
Community & Business
Active development 0.5
Commercial support
Live community
Open Source ·
Pricing ·
Trendiness
Deployment
Containerization
Work as dedicated instance
Work as embedded ·
Testing in-memory version ·
Platform
Operating on Linux
Operating on Windows ·
SaaS offering
Operations
Automatic updates ·
Client side caching ·
Data versioning support ·
Live backups
Distribution
Cluster Re-balancing ·
Data Distribution ·
High-Availability
Query Distribution
Replication support
Developer Experience
Data types defined 0.5
Logging/Auditing
Object-Graph Mapper ·
Reactive programming
Documentation up-to-date
Binary protocol ·
CLI
GUI
Data Model
Multi-database
Graph-native data ·
REST API
Query Language
Transactions
Granular locking
Multiple isolation levels
Read committed transaction ·
Transaction support
Schema & Security
Constraints
Schema support
Secondary indexes
Server side procedures
Triggers ·
Authentication
Authorization
Data encryption ·