A new application I was installing wanted the mysqli_fetch_all method, which is available from the mysqlnd native MySQL driver. But yum wouldn’t install it because of a conflict with the already installed original mysql driver package.
I’m using the IUS Repository php54 packages to allow a Red Hat Enterprise Linux 6 server to run programs that require php 5.4 or newer. The “original” php54-mysql package was installed by default as part of an upgrade from the shipping rpms. But now I needed php54-mysqlnd package, which contains the “native” MySQL driver that supports the mysqli_fetch_all method.
The solution turned out to be simple: just remove php54-mysql and then install php54-mysqlnd. Fortunately I’m not running anything that requires the old driver. In fact php-mysql isn’t even available for Fedora 21.