HSQLDB (HyperSQL DataBase) is the leading SQL relational database engine written in Java. It supports nearly full ANSI-92 SQL (BNF format) and full core SQL:2008. It offers a small, fast multithreaded and transactional database engine with in-memory and disk-based tables and supports embedded and server modes. It includes tools such as a command line SQL tool and GUI query tools.
HSQLDB supports the widest range of SQL Standard features seen in any open source database engine: SQL:2008 core language features and an extensive list of SQL:2008 optional features. Many extensions to the Standard, including features of other popular database engines, are also supported.
Version 2.2 is fully multithreaded and supports high performance 2PL and MVCC (multiversion concurrency control) transaction control models. See the list of new features in version 2.2.
HSQLDB is known for its small size, ability to execute completely or partly in memory, its flexibility and speed.
HSQLDB is completely free to use and distribute under HyperSQL DataBase licenses, which are based on the standard BSD license and fully compatible with all major open source licenses.
Latest stable version available for download is HyperSQL 2.2.6.
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