The emergence of MillenniumDB, a new graph-oriented database management system, has sparked an engaging discussion among database experts about the current state and future of RDF (Resource Description Framework) and graph database technologies.
Production Readiness and Alternatives
While MillenniumDB shows promise as a research project from the well-regarded Chilean research group, the community discussion reveals a complex landscape of RDF database options. Enterprise users currently gravitate toward established solutions like Stardog, Ontotext GraphDB, and AWS Neptune for production environments, though these come with significant licensing costs. For newcomers and experimental projects, lighter alternatives like Oxigraph and RDF4J are gaining traction.
If you expect Jena to be more battle-tested because it is older, forget it, if the process is killed by a unexpected shutdown or some other reason it results in data corruption.
Key Database Alternatives:
- Enterprise: Stardog, Ontotext GraphDB, AWS Neptune
- Open Source: Apache Jena/Fuseki, Eclipse RDF4J, Oxigraph
- Research/Development: MillenniumDB, QLever
Current Limitations in MillenniumDB's SPARQL Support:
- No support for named graphs
- Limited update operations (only INSERT DATA and DELETE DATA)
- No FROM clause support
- No GRAPH keyword support
- Limited regular expression support
Technical Challenges in RDF Systems
A significant point of discussion centers around SPARQL's transactional capabilities and record management. Unlike traditional SQL databases, RDF systems face unique challenges in handling updates and maintaining data integrity. The lack of an intrinsic concept of records in SPARQL databases requires careful implementation of transactional boundaries and disciplined application design.
Performance and Scalability Considerations
Database experts highlight that modern RDF systems like MillenniumDB and QLever are making strides in reducing the operational costs of hosting SPARQL endpoints, potentially offering one to two orders of magnitude improvement in cost-efficiency. This development is particularly significant for organizations providing RDF data and exposing SPARQL endpoints.
Future Developments
The community expresses a clear need for improvements in several areas, including better handling of ordered collections, more efficient production rules, and enhanced transaction management. There's particular interest in the potential development of a SPARQL 2.0 that could address current limitations while maintaining the flexibility and power of graph-based data modeling.
Integration and Practical Applications
Practitioners emphasize the importance of considering specific use cases when selecting a graph database solution. While MillenniumDB supports both RDF and Property Graph models, each with its corresponding query language, the choice between different systems often depends on factors such as update frequency, query patterns, and integration requirements with existing systems.
Reference: MillenniumDB: A Graph-Oriented Database Management System