Updating yum repositories
However Fedora 22 ships with DNF implemented officially.To install DNF on RHEL/Cent OS systems, you need to first install and enable epel-release repository.My observation: DNF does not downgraded the package as it is supposed to. DNF is the upper state of the end of the art Package Manager YUM.It tends to do a lot of processing automatically which is not going to be praised by many experienced Linux System Administrator, as I believe.A lot of time we encounter out-of-date headers and unfinished transactions which results into error while executing dnf.We may clean all the cached packages and headers containing remote package information simply by executing.DNF aims at improving the bottlenecks of YUM viz., Performance, Memory Usages, Dependency Resolution, Speed and lots of other factors.DNF does Package Management using RPM, libsolv and hawkey library.
The following RPM packages from the native software repositories of the platforms are incompatible with the package from the My SQL Yum repository that installs the My SQL server.
As a popular, open-source software, My SQL, in its original or re-packaged form, is widely installed on many systems from various sources, including different software download sites, software repositories, and so on.
The following instructions assume that My SQL is not already installed on your system using a third-party-distributed RPM package; if that is not the case, follow the instructions given in Section 18.104.22.168, “Upgrading My SQL with the My SQL Yum Repository” or Section 2.5.2, “Replacing a Third-Party Distribution of My SQL Using the My SQL Yum Repository”.
Once you have installed My SQL using the My SQL Yum repository, you will not be able to install these packages (and vice versa).
You can use Yum to install and manage individual components of My SQL.