This is an archived version of the documentation for SonarQube version 6.4.
See Documentation for current functionality
The data migration performed during the upgrade to SonarQube 6.0 induces high fragmentation on some of the tables. On big databases, this can impact performances of SonarQube. As documented on the Upgrading page, this is highly recommended to refresh your database's statistics and rebuild your database's indices once the technical upgrade is done.