I’ve researched this a few times, yet my searching does not reveal much except custom code which may or may not be good WordPress practice.

As of the latest releases (WordPress 3.9 “Smith”), has a hook been added to the plugin update process? I’m asking because its a very basic need, yet I do not see it added to the codex (yet). If not, what is the common and best practice developers employ?

EDIT: Just to clarify, I’m not talking about activation, but about updating, that way, if there are changes in database or otherwise it can be addressed.