As I've been poking around in this area, I find myself growing increasingly annoyed at the new GUC name "debug_invalidate_system_caches_always". It is too d*mn long. It's a serious pain to type in any context where you don't have autocomplete to help you. I've kept referring to this type of testing as CLOBBER_CACHE_ALWAYS testing, even though that name is now obsolete, just because it's so much shorter. I think we need to reconsider this name while we still can.
I do agree with the "debug_" prefix given that it's now visible to users. However, it doesn't seem that hard to save some space in the rest of the name. The word "system" is adding nothing of value, and the word "always" seems rather confusing --- if it does something "always", why is there more than one level? So a simple proposal is to rename it to "debug_invalidate_caches". However, I think we should also give serious consideration to "debug_clobber_cache" or "debug_clobber_cache_always" for continuity with past practice (though it still feels like "always" is a good word to lose now). "debug_clobber_caches" is another reasonable variant. Thoughts? regards, tom lane