For some distributions you can build MariaDB from a source RPM. (See also Why Source RPMs (SRPMs) Aren't Packaged For Some Platforms).

You can build it as follows:

using dnf

On RHEL8 you might need to start with:

    sudo dnf config-manager --set-enabled codeready-builder-beta-for-rhel-8-x86_64-rpms

Then, on all dnf distributions:

    sudo dnf install rpm-build perl-generators
    dnf download --source MariaDB
    sudo dnf builddep MariaDB-*.src.rpm
    rpmbuild --rebuild MariaDB-*.src.rpm

using yum

    sudo yum install rpm-build yum-utils
    yumdownloader --source MariaDB
    sudo yum-builddep MariaDB-*.src.rpm
    rpmbuild --rebuild MariaDB-*.src.rpm

using zypper

    sudo zypper in rpm-build
    sudo zypper si MariaDB
    sudo rpmbuild -bb /usr/src/packages/SPECS/MariaDB.spec

Or (to avoid building as root):

    sudo zypper in rpm-build
    sudo zypper si -d MariaDB
    zypper --pkg-cache-dir=`pwd` si --download-only MariaDB
    rpmbuild --rebuild mariadb/srpms/MariaDB-*.src.rpm