On 3rd of October, Andres Freund committed patch:
Add CASCADE support for CREATE EXTENSION. Without CASCADE, if an extension has an unfullfilled dependency on another extension, CREATE EXTENSION ERRORs out with "required extension ... is not installed". That is annoying, especially when that dependency is an implementation detail of the extension, rather than something the extension's user can make sense of. In addition to CASCADE this also includes a small set of regression tests around CREATE EXTENSION. Author: Petr Jelinek, editorialized by Michael Paquier, Andres Freund Reviewed-By: Michael Paquier, Andres Freund, Jeff Janes Discussion: <a class="text" href="/gitweb/?p=postgresql.git;a=object;h=557E0520">557E0520</a>.3040800@2ndquadrant.com
Continue reading Waiting for 9.6 – Add CASCADE support for CREATE EXTENSION.