I understand that the post Id is local but, is there a way to generate a global link that contains the information about the server, community and post?
I think it will be useful to make mirror sites, index in Google, addons to redirect to your Lemmy server...
Part of the idea behind federation is that by only accessing content through your specific instance, you actually reduce the load on the instance you're browsing to, because your specific instance federates (essentially "caches") a local copy of the remote content. So by trying to obtain a direct "global" link to the original you're bypassing a lot of the natural load sharing and that is inherently undesirable for very large instances like lemmy.ml is becoming. As long as federation is working smoothly, you are losing no inherent information about the post by sharing a link to the post from your lemmy.world instance vs lemmy.one, lemmy.ml, or any other instance, whether the post is original to that instance or no.
Besides, the information about the "server/community/post" is sort of baked into Lemmy's UI with how it defines locations within Lemmy (eg. Technology@beehaw.org, tells you right off the bat the community is on the Beehaw instance, same for users). That's just down to user's learning knowledge about how the Lemmy system is laid out and displayed in the UI.
Balance the load across multiple instances is fine. I don't want the permalink to access the lemmy.ml domain always, it is just in case something happens to the instance lemmy.ml, it will me much easier to replace the domain in my bookmarks.
My feeling is that nobody is thinking about long term storage/search/archival. Lemmy/Reddit is a forum for me and I like to bookmark some posts and revisit them from time to time. In the next months many instances will shut down, accounts, posts, links... will be lost. Having universal URIs is a must and hving some kind of tool to migrate users across servers too.
This is actually quite strange to me - that lemmy doesn't use permalinks by default. When viewing from a non-source instance, there's a link button between the comment count and the save button that takes you to the post on the source instance, but that seems inadequate. I guess the post on the origin instance is its own permalink, but I don't like that it's not distinct in some way.