HSQLDB
HSQLDB is a Java-based relational database engine with in-memory and disk-based tables, available in embedded and server modes.
What HSQLDB is
HSQLDB is a Java-based relational database engine with in-memory and disk-based tables, available in embedded and server modes. It supports SQL:2023 core features and an extensive set of optional features. Transaction options include lock-based and MVCC models, and the engine is fully multithreaded. 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; packages include Java 11 module jars and Java 8 jars for HSQLDB and SQL Tool. The project lists integrations with OpenOffice and LibreOffice, and names Spring, Hibernate, Flyway, Liquibase, DBeaver, and Eclipse. It is free to use in commercial products when license terms are met; licenses are based on the new BSD License. The free plan is free. Paid options include a Developer subscription at $100 a year and a Premier Corporate subscription at $2,500 a year at the base level. It is self-hosted.
Good
- Offers embedded and server modes.
- Supports lock-based and MVCC transactions.
- Includes JSON, CSV, and temporal table features.
- Commercial use is permitted when license terms are met.
- Provides command-line and GUI query tools.
Watch out
- Memory tables are limited by available memory.
- TEXT tables are limited to 256GB each.
- CACHED table size defaults to 8TB combined.
- Paid subscriptions include unlisted Basic Corporate pricing.
Who it suits
HSQLDB may suit developers and organizations seeking a self-hosted Java database with embedded or server operation. Its listed tools and integrations may also be relevant to teams using the named Java and database projects.
Verdict
HSQLDB provides a range of database features and developer tools in a self-hosted Java engine. Review its license terms, storage limits, and support subscription options before choosing it.
Plans and prices
From HSQLDB's own pricing page, checked 22 Sep 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Developer subscription | $100 a year | Priority support · Input into future development · Annual subscription |
| Basic Corporate subscription | — | Less than 50 distributed units |
| Premier Corporate subscription | $2,500 a year | For large corporations and large-scale use or distribution · Full deployment support · Enhancement requests · Base level; annual subscription |
| HSQLDB software | Free | Open-source database engine · embedded or server modes · Free to use and distribute under BSD-based licenses |
| HSQLDB | Free | Database software is free to use and distribute under its licenses |
| Developer SupportWare | $100 a year | Individual developer · priority support · input into future development · Annual subscription |
| SupportWare Developer subscription | $100 a year | Individual developers; priority questions and a say in future development · $100 annually |
| Basic Corporate SupportWare | $500 a year | Corporations with limited internal use or fewer than 50 distributed units · priority support and feature input · Annual subscription; $500-$1,000 |
| SupportWare Basic Corporate subscription | $500 a year | Corporations with limited internal use or fewer than 50 distributed units; priority support and input on future development · $500-$1000 annually |
| Premier Corporate SupportWare | $2,500 a year | Large-scale use or distribution · enhancement requests · full deployment support · Annual subscription; base level |
| SupportWare Premier Corporate subscription | $2,500 a year | Large corporations or large-scale use or distribution; deployment support and enhancement requests · Base level $2500 annually |
The facts
Each one read from HSQLDB's own pages, with the date it was checked.
What it does
- Backup
- The engine supports fast startup and shutdown with incremental backup plus online and offline backups and SQL-script dumps.checked 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.checked 15 Oct 2026
- Concurrency
- The engine is multithreaded and offers lock-based, MVCC and hybrid transaction-control models.checked 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.checked 7 Oct 2026
- Deployment protocols
- Embedded and client-server operation are supported through HSQL, HTTP and HSQL-BER protocols, each with an SSL option.checked 15 Oct 2026
- Developer tooling
- The distribution includes SQLTool command-line administration, two GUI database managers, a transfer utility and a test/script utility.checked 15 Oct 2026
- Developer tools
- The product includes a command-line SQL tool and simple GUI query tools.checked 7 Oct 2026
- Distribution
- The release package includes Java 11 module jars and Java 8 jars for HSQLDB and SQL Tool.checked 7 Oct 2026
- Documentation depth
- The project publishes HTML, PDF and text guides, JavaDoc for public classes, utilities documentation, examples, tests and SQL scripts.checked 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.checked 15 Oct 2026
- Installation requirement
- Installation consists of downloading and unpacking hsqldb.zip and requires a Java Runtime Environment or JDK.checked 15 Oct 2026
- Integrations
- The project documents JDBC and ODBC connectivity and integration with OpenOffice.org and LibreOffice.checked 15 Oct 2026
- Java compatibility
- The latest official release listed is version 2.7.4, which works with JDK 8 and above.checked 7 Oct 2026
- Java support
- HSQLDB is written entirely in Java; the standard jar targets Java 11+ while an alternative jar supports Java 8+.checked 15 Oct 2026
- JDBC API
- It provides extensive JDBC support including batch statements, scrollable and updatable ResultSets, metadata, CallableStatement and PreparedStatement.checked 15 Oct 2026
- Latest release
- The official latest release is version 2.7.4, dated 25 October 2024.checked 15 Oct 2026
- License
- HSQLDB source and binaries use permissive BSD-based licenses, with separate terms for legacy Hypersonic SQL code.checked 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.checked 15 Oct 2026
- Limit: SourceForge debugging
- A critical SourceForge review complained that older error messages did not identify the failing table or column, making debugging laborious.checked 15 Oct 2026
- Limit: SourceForge DSV handling
- A reviewer reported that an older SqlTool DSV export failed to escape quotes and line breaks, preventing reliable re-import of multiline data.checked 15 Oct 2026
The company
- Founded
- 2001checked 28 Sep 2026
- Maker
- HSQLDB is developed and published by The HSQL Development Group, formed in 2001.checked 7 Oct 2026
- Maker and founding
- The HSQL Development Group is the publisher and says it was formed in 2001.checked 15 Oct 2026
Money
- Free plan
- Yeschecked 22 Sep 2026
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