Who is using the alternative database system MariaDB at Debian and is updating some packages via Dotdeb have had the problem that updates of MariaDB can´t be installed. Error message: “the following packages have been kept back”. Reason is the versioning between MariaDB and mysql-common. You´ll find one solution at the link, but for me this didn´t work.
The best solution is to implement an option, which prefers MariaDB packages. You can set this on Debian at /etc/apt/preferences.d/
At this place I´ve created a file named 50_mariadb.pref. This file has to be named like I´ve written it in order to get the preferences for MariaDB working.
When you open this file with nano write:
[AdSense-A]
Package: *
Pin: origin "mirrors.n-ix.net"
Pin-Priority: 1000
In most solutions the quotation marks are missing, but these have to be set (regarding to man). At my code snippet I´ve inserted a mirror from the MariaDB 5.5 Repository. In general: Get the link from sources-list, remove http and everything after the top level domain and insert the rest between the quotation marks. Done!
apt-get update, apt-get upgrade and everything should work again.