# H2

An embeddable, open-source relational database for Java, usable in-memory or on disk, in embedded or server mode, over a JDBC API.

H2 is a Java SQL database. It is very fast, open source, and exposes a JDBC API, running in embedded or server mode, backed by disk-based or in-memory databases, and it also includes an ODBC driver.

It supports transactions with multi-version concurrency, encrypted databases, and full-text search, and ships a browser-based console application for interacting with a database directly. As pure Java with a small footprint, its jar file is only around 2.5 MB. It is added to a project such as through a Maven dependency, and its documentation includes a tutorial, a reference of SQL commands, functions and data types, an issue tracker for bugs and feature requests, and a mailing list and Stack Overflow tag for questions.

Website: https://h2database.com