So, 42.3 inherits PostgreSQL from SLE? We usually push PostgreSQL on SLE to the latest patchlevel of the respective release when it contains security fixes and skip the bugfix-only patchlevels in between, but I see no problem to push the latest 9.4.11 to SLE12 if it helps avoiding a split of 42.3. BTW, we currently plan to upgrade SLE12 to PostgreSQL 9.6, which will be provided in parallel to 9.4 for some time. https://fate.suse.com/321481