ActorDB vs VoltDB

ActorDB is an open-source distributed relational SQL database from Biokoda that organizes data into independent actors. SQLite handles SQL queries and LMDB provides storage. Applications connect through the MySQL protocol or Thrift, and the FAQ recommends Thrift; default MySQL drivers also work. ActorDB uses Raft for distributed consensus and write replication, and describes itself as strongly consistent. Transactions can span multiple actors and are described as ACID compliant. It can also provide a sharded key-value store with structured values, multiple columns, and foreign tables. The maker says horizontal scaling can reach hundreds of nodes and petabytes when data is spread across actors. If a server fails, a follower can lead an actor while a cluster majority remains online. Recommended cluster sizes are 1, 3, or 5 nodes. Supported downloads include Windows, Mac OS X, CentOS, and Ubuntu, with version 0.10.29 dated 1 October 2019 shown as the latest stable release.

VoltDB is a distributed, in-memory database and real-time decisioning layer for data processing, stream ingestion, business logic, and AI integration. Its database partitions data and stored procedures so queries can run in parallel while maintaining ACID consistency. Volt Active Data says Volt is built to move from ingest to action in under 10 milliseconds. Clusters scale by adding nodes, with partitioning automated from the schema. Volt connects directly to Kafka or CDC streams and can expose decisions through SQL, REST, or Kafka topics. It supports on-premises, cloud Kubernetes or VM-based, and hybrid deployments. Production databases support Debian 12.11 or later, RHEL 8.8 or later, Rocky Linux 8.8 or later, and Ubuntu 20.04, 22.04, or 24.04; macOS 13 or later is supported for development. Enterprise Edition provides command logging, locally replicated partitions, and wide-area database replication. Authentication, role-based authorization, and TLS/SSL or Kerberos communications are available, but security is disabled by default. The free Developer Edition is not intended for production workloads. A free 30-day trial is listed for Confluent users; production pricing is on request.