In Fedora 22, the postgresql packages have been updated to the upstream version 9.4.1, which provides various bug fixes and enhancements described on upstream 9.4.0 release notes and 9.4.1 release notes pages.
Migration to 9.4 version is possible by post-upgrde script
postgresql-setup (meaning that you may firstly update your Fedora instalation from version 21 to 22 and then perform database stack update to 9.4). Users are however encouraged to do full database dump for backup purposes before Fedora upgrade to 22. For more info about migration look into the README.rpm-dist file distributed in