Details
- Vendor
- IMFD Chile
- Type
- Multiple
- Category
- Emerging
- License
- GPL-2.0
- Language
- C++
- Query Languages
- GQLSPARQL
- Protocols
- SPARQL ProtocolWebSocket
MillenniumDB
An open-source, multi-model graph database supporting property graphs, RDF, and a multilayered graph format. Built on relational storage techniques and worst-case optimal join algorithms, with query support via SPARQL 1.1, GQL, and a proprietary Cypher-like language.
- Overall rank
- #91
- First released
- 2021
- License
- GPL-2.0
- Built with
- C++
Details
Sources 6 references
Protocols SPARQL Protocol, WebSocket
RDF/SPARQL queries go through the SPARQL server implementing the W3C SPARQL Protocol (default port 1234); the official MQL/property-graph drivers (Python, JS) connect over a ws:// WebSocket URL rather than plain HTTP. Draft's generic HTTP/REST tag is corrected to WebSocket for the non-SPARQL client path.
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The MillenniumDB SPARQL server supports all three query operations specified in the SPARQL Protocol:
Client-Server — MillenniumDB 0.2 documentation · reviewed 2026-08-02 -
import millenniumdb_driver url = 'your-server-url' # e.g. ws://localhost:1234
MillenniumDB/MillenniumDB-driver-python · reviewed 2026-08-02
License GPL-2.0
SPDX identifier as classified by GitHub from the repository licence file.
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"spdx_id": "GPL-2.0"
GitHub licence API — MillenniumDB/MillenniumDB · reviewed 2026-08-02
Released 2021
Confirms current value. IMFD's systems paper describes the first public release of the MillenniumDB engine and was itself published in 2021.
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We further publish a first release of MillenniumDB as an open source graph database engine
MillenniumDB: An Open-Source Graph Database System · reviewed 2026-08-02
Language C++
Confirms current value. GitHub byte counts show C++ (8.0MB) dwarfing every other language, and the project's own developer docs are about compiling the C++ core with CMake/Clang.
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"C++":8041383,"HTML":2248716,"ANTLR":132014,"Python":96748,"C":48285
MillenniumDB/MillenniumDB languages (GitHub API) · reviewed 2026-08-02 -
Sometimes when you install clang via the package manager, it won’t be recognized by cmake as a C++ alternative.
General Developer Setup — MillenniumDB 0.2 documentation · reviewed 2026-08-02