A distribution upgrade, performed by running: , will upgrade (or downgrade) all installed packages to the latest version listed in every enabled repository, and as such, it should be used with caution.The upgrade operation will be performed regardless of vendor or repository and is often used when you want to replace an official package with one from a 3rd party repository, such as packman.On a production system or system that needs to be kept in a stable state you will not want to use the dist-upgrade option except in certain situations.
I would highly recommend spending some time reading the zypper man pages if you are planning to do any serious work with zypper.
As I’ve said before zypper is a great (probably the best) package manager that is available in any Linux distribution.
The focus of its development is creating usable open-source tools for software developers and system administrators, while providing a user-friendly desktop and feature-rich server environment.
This is based on the rolling development code base called 'Factory'.
A package with an updated version number that doesn’t match a “fix” for a bug or security flaw will not be included in a patch.
Installing “Patches” rather than “Updates”, strictly speaking, is probably only necessary for production environments that can only handle minimal changes to installed packages, while still maintaining a secure system.
A single patch might include several package updates to mitigate a specific security vulnerability or bug fix.
In many cases installing patches will not fully update your system.
However, if you want to ensure that you have a stable and undisturbed desktop experience, there is certainly nothing wrong with limiting your updates to patches.
One of the great things about working with patches is the vast amount of information that is available for them that can be accessed straight from the command line.
Zypper update is a safe and reliable way to update any Open SUSE or SUSE Enterprise Linux system, without worrying about major version changes.