JIRA安装时使用默认内置的h2数据库，使用一段时候后，需要切换到其他类型数据库
支持的数据库类型和版本
- 备份系统已有数据
Create an export of your data as an XML backup.
- 新建JIRA数据库
Create a new database on your new database server to house JIRA‘s data. See the appropriate database configuration guide in the Connecting JIRA to a database section for the database creation instructions.
- 停止JIRA服务，并备份JIRA目录
Shut down your JIRA server.
Make a backup of your JIRA home directory and JIRA installation directory.
- 删除dbconfig.xml文件，重启JIRA进入配置向导页
Delete the dbconfig.xml file in your JIRA home directory.
Restart JIRA and you should see the first step of the JIRA setup wizard for configuring your database connection.
- 配置连接到新的数据库
Configure JIRA‘s connection to your new database (created in step 2 above) and click the ‘Next‘ button.
- 导入备份数据
On the ‘Application Properties‘ setup page, click the ‘import your existing data‘ link and restore your data from the XML backup created in step 1 above.