Jira stores all its data in a relational database. While you can run Jira with H2 Database, the in-memory database that comes bundled with Jira, it is prone to data corruption. You should only use this to set up a new instance quickly for evaluation purposes, where no important data will be stored. For this reason, it is important that you use a proper database such as MySQL for production systems.

Most relational databases available on the market today are supported by Jira, and there are no differences when you install and configure Jira. Just like operating systems, your choice of database will come down to your IT staff's expertise, experience, and established corporate IT standards. If you run Windows as your operating system, then you probably want to go with the Microsoft SQL Server. On the other hand, if you run Linux, then you should consider Oracle (if you already have a license), MySQL, or PostgreSQL.

The following table summarizes the databases that are currently supported by Jira. It is worth mentioning that both MySQL and PostgreSQL are open source products, so they are excellent options if you are looking to minimize your initial investments.

Take special note of the driver requirement on each database, as some drivers that come bundled with the database vendor or Jira itself (for example, PostgreSQL) are not supported and will need to be replaced with the appropriate versions.