NOTE: This suggestion is for JIRA Server. Using JIRA Cloud? See the corresponding suggestion.
Percona DB (http://www.percona.com/software) is a flavor of MySQL, however is not yet supported by JIRA. Based on earlier support cases and tests, JIRA does not work well with this database type yet.
Add support for MariaDB to Stash
Support for Percona DB
Add MariaDB as a supported platform for Jira
Add support to Percona's distribution of MySQL
JIRA to support Percona DB
Documentation request: mention not supported flavors of MySQL
Support for PerconaDB