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XTDB
What XTDB is
XTDB is an immutable SQL database for applications that need historical records, reporting or auditability. Its bitemporal model records when data was valid and when the system recorded it, so queries can examine both timelines. XTDB supports SQL:2011 temporal queries and a broader SQL dialect through FlightSQL and PostgreSQL wire compatibility. It handles flexible schemas and semi-structured data, and supports PostgreSQL-compatible SERIALIZABLE transactions with optimistic concurrency. For storage and analytics, it uses an object-store LSM-tree design and Apache Arrow for temporal analytics and scale-out compute. XTDB can run in Docker, on premises or through cloud marketplaces. Apache Kafka can serve as a message log, with Kafka Connect as an external source. Authentication options include a root user, a configured user list and OpenID Connect providers. XTDB is open source under the MPL license and has a free plan. Support options include community support, consulting, training and annual production support subscriptions; the Developer Edition is listed at $2,000 a year.
Who it suits
XTDB may suit developers augmenting existing applications or building new ones that need historical state, auditability or temporal reporting. It offers deployment choices from Docker to on-premises and cloud marketplaces.
What it does well
- Free and open source under the MPL license.
- Queries across valid time and system time.
- Supports SQL:2011 temporal queries.
- Docker, on-premises and cloud marketplace deployment options.
- Kafka and Kafka Connect support.
What to know first
- Developer Edition is listed at $2,000 a year.
- Authentication options are limited to listed user methods and OpenID Connect.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Partner Pack | $0/year · Community support · Private Zulip stream · Early access to releases · Feedback channel · Partner network | Free |
| Developer Edition | $2k/year · Partner Pack features · Official support · Private issue tracker · Upgrade guidance · UK business hours response SLA | $2,000 a year |
| Production Support | Developer Edition features · Private release channels · Rapid hotfix service · Core team consultations · 24/7 SLA | On request |
As xtdb.com lists them, read 7 Oct 2026. The maker's own page has the final word.
Verdict
XTDB focuses on keeping historical state queryable through bitemporal records and SQL. Its deployment and support options may fit a range of application setups, but check the listed support plan terms before adopting it.
Facts from XTDB's own pages
- Audience
- The maker describes XTDB as useful for augmenting existing applications and building new applications that need auditability and historical state. · xtdb.com, 7 Oct 2026
- Authentication
- XTDB supports a single root user, a configured user list, and OpenID Connect authentication providers. · docs.xtdb.com, 7 Oct 2026
- Bitemporal history
- XTDB records bitemporal history so users can query data across valid time and system time. · docs.xtdb.com, 7 Oct 2026
- Deployment
- XTDB can run using Docker and is also available for on-premises deployment and through cloud marketplaces. · xtdb.com, 7 Oct 2026
- Headquarters
- London, United Kingdom · xtdb.com, 28 Sept 2026
- Integrations
- XTDB supports Apache Kafka as a message log and Kafka Connect as an external source. · docs.xtdb.com, 7 Oct 2026
- License
- XTDB is free to use and open source under the MPL license. · docs.xtdb.com, 7 Oct 2026
- Purpose
- XTDB is an immutable SQL database designed to simplify development, reporting, and compliance for systems that need historical records. · xtdb.com, 7 Oct 2026
- Schema
- XTDB supports flexible schema and first-class handling of semi-structured data. · xtdb.com, 7 Oct 2026
- SQL
- XTDB supports SQL:2011 temporal queries and a rich SQL dialect through FlightSQL and PostgreSQL wire compatibility. · xtdb.com, 7 Oct 2026
- Storage and compute
- XTDB uses an object-store LSM-tree design and Apache Arrow for temporal analytics and scale-out compute. · xtdb.com, 7 Oct 2026
- Support
- The maker offers annual production support subscriptions, community support, consulting, and training. · xtdb.com, 7 Oct 2026
- Transactions
- XTDB supports PostgreSQL-compatible SERIALIZABLE SQL transactions with optimistic concurrency. · xtdb.com, 7 Oct 2026
Where XTDB stands on Freedom251
- Data Version Control Tools#29 of 36