AllegroGraph vs QLever

AllegroGraph is a persistent graph database for RDF triples and quads, generic graphs, and vectors, using disk-based storage and efficient memory utilization. It supports SPARQL, RDFS++ reasoning, and Prolog, plus geospatial and temporal reasoning, social network analysis, native data types, and range queries. The database is ACID-compliant and includes online backups, point-in-time recovery, replication, and warm standby. It can integrate with large language models and store embedding vectors in a vector database. Security features include role-based permissions, repository access controls, security filters, and triple-level controls using attributes. LDAP and OAuth/OIDC authentication are supported, with TLS for client connections; the security overview recommends third-party tools for encryption at rest. Clients include Java, Python, and Lisp, alongside REST and browser-based WebView access. The server runs natively on x86-64 Linux, with documented Docker, Windows Subsystem for Linux, virtual machine, and cloud options. The free edition costs nothing, has no expiration or license key requirement, and allows up to 5,000,000 triples.

QLever is an open-source graph database for loading and querying large RDF datasets. It implements SPARQL 1.1, including federated queries, named graphs, the Graph Store HTTP Protocol, and updates. The project says it can handle more than a trillion triples on a single commodity machine. It also provides text search over knowledge bases, context-sensitive SPARQL autocompletion, live query analysis, and spatial queries with interactive maps of large sets of geometric objects. QLever can run embedded inside C++ code without a client-server setup. Example datasets include Wikidata, Wikimedia Commons, OpenStreetMap, UniProt, PubChem, and DBLP. It is self-hosted, with official packages for Debian, Ubuntu, Ubuntu-derived distributions, and macOS, plus Docker and Podman images. The official Homebrew package supports ARM64 Apple Silicon Macs, not Intel Macs. Windows use runs Docker inside a virtual machine and may incur significant performance and RAM costs; binary releases are in progress. QLever is free under the Apache 2.0 license.