- Home
- Relational Databases
- HSQLDB
HSQLDB
HSQLDB · founded 2001
What it is
HSQLDB is a Java-based relational database engine with in-memory and disk-based tables, supporting embedded and server modes. It supports SQL:2023 core features and an extensive set of optional features, with lock-based and MVCC transaction models and multithreaded operation. Listed capabilities include JSON constructor functions, CSV loading and unloading, temporal system-versioned tables, row-level access control, and log-based replica synchronization. Developer tools include a command-line SQL tool and simple GUI query tools. The latest official release listed is version 2.7.4, which works with JDK 8 and above; release packages include Java 11 module jars and Java 8 jars for HSQLDB and SQL Tool. HSQLDB is self-hosted and lists high availability, read replicas, and JSON data support. The software is free to use in commercial products when license terms are met; its licenses are based on the new BSD License. Support options include a help forum, user mailing list, trackers, paid SupportWare, and professional commercial support. The Developer subscription costs $100 a year, while the Premier Corporate subscription costs $2,500 a year at its base level. Storage limits vary by table type, and memory tables depend on available memory.
For and against
For
- Supports embedded and server modes.
- Offers lock-based and MVCC transaction models.
- Includes command-line and GUI query tools.
- Free commercial use is available under license terms.
- Lists high availability and read replicas.
Against
- Memory tables are limited by available memory.
- TEXT tables are limited to 256GB each.
- Premier Corporate starts at $2,500 a year.
The verdict
HSQLDB offers a broad relational database feature set and several developer tools in a self-hosted package. Review the license terms, storage limits, and support subscription options against the intended deployment.
Who it suits
HSQLDB suits developers and organizations looking for a self-hosted Java relational database with embedded or server deployment. Its SQL tools, integrations, and support options are relevant to teams building or managing database-backed applications.
Plans and prices
Developer subscription
Priority support · Input into future development
Read 22 Sep 2026 · hsqldb.org
Basic Corporate subscription
Less than 50 distributed units
Read 22 Sep 2026 · hsqldb.org
Premier Corporate subscription
For large corporations and large-scale use or distribution · Full deployment support · Enhancement requests
Read 22 Sep 2026 · hsqldb.org
HSQLDB software
Open-source database engine · embedded or server modes
Read 15 Oct 2026 · hsqldb.org
Developer SupportWare
Individual developer · priority support · input into future development
Read 15 Oct 2026 · hsqldb.org
Basic Corporate SupportWare
Corporations with limited internal use or fewer than 50 distributed units · priority support and feature input
Read 15 Oct 2026 · hsqldb.org
Premier Corporate SupportWare
Large-scale use or distribution · enhancement requests · full deployment support
Read 15 Oct 2026 · hsqldb.org
HSQLDB
Database software is free to use and distribute under its licenses
Read 7 Oct 2026 · hsqldb.org
SupportWare Developer subscription
Individual developers; priority questions and a say in future development
Read 7 Oct 2026 · hsqldb.org
On the record
- Backup
- The engine supports fast startup and shutdown with incremental backup plus online and offline backups and SQL-script dumps.hsqldb.org · read 15 Oct 2026
- Capacity
- Official limits include disk tables up to 8 TB, text tables up to 256 GB and individual CLOB/BLOB storage up to 64 TB.hsqldb.org · read 15 Oct 2026
- Concurrency
- The engine is multithreaded and offers lock-based, MVCC and hybrid transaction-control models.hsqldb.org · read 15 Oct 2026
- Data storage limit
- The FAQ states the default combined size limit for CACHED tables is 8TB, extendable to 256TB with a connection property; TEXT tables are limited to 256GB each.hsqldb.org · read 7 Oct 2026
- Deployment protocols
- Embedded and client-server operation are supported through HSQL, HTTP and HSQL-BER protocols, each with an SSL option.hsqldb.org · read 15 Oct 2026
- Developer tooling
- The distribution includes SQLTool command-line administration, two GUI database managers, a transfer utility and a test/script utility.hsqldb.org · read 15 Oct 2026
- Developer tools
- The product includes a command-line SQL tool and simple GUI query tools.hsqldb.org · read 7 Oct 2026
- Distribution
- The release package includes Java 11 module jars and Java 8 jars for HSQLDB and SQL Tool.hsqldb.org · read 7 Oct 2026
- Documentation depth
- The project publishes HTML, PDF and text guides, JavaDoc for public classes, utilities documentation, examples, tests and SQL scripts.hsqldb.org · read 15 Oct 2026
- Extensibility
- Applications can define Java stored procedures, Java or SQL triggers, aggregate functions and routines with INOUT parameters and multiple result sets.hsqldb.org · read 15 Oct 2026
- Installation requirement
- Installation consists of downloading and unpacking hsqldb.zip and requires a Java Runtime Environment or JDK.hsqldb.org · read 15 Oct 2026
- Integrations
- The project documents JDBC and ODBC connectivity and integration with OpenOffice.org and LibreOffice.hsqldb.org · read 15 Oct 2026
- Java compatibility
- The latest official release listed is version 2.7.4, which works with JDK 8 and above.hsqldb.org · read 7 Oct 2026
- Java support
- HSQLDB is written entirely in Java; the standard jar targets Java 11+ while an alternative jar supports Java 8+.hsqldb.org · read 15 Oct 2026
- JDBC API
- It provides extensive JDBC support including batch statements, scrollable and updatable ResultSets, metadata, CallableStatement and PreparedStatement.hsqldb.org · read 15 Oct 2026
- Latest release
- The official latest release is version 2.7.4, dated 25 October 2024.hsqldb.org · read 15 Oct 2026
- License
- HSQLDB source and binaries use permissive BSD-based licenses, with separate terms for legacy Hypersonic SQL code.hsqldb.org · read 15 Oct 2026
- Limit: Capterra scale
- One Capterra reviewer says the embedded database is not suitable for a large project, and another notes it is unsupported in newer SAP Commerce Cloud versions.capterra.com · read 15 Oct 2026
