While shutting down terminal windows to the SN servers this morning, one of them had the create table syntax for the comments table still on screen. I gave it a read through just because it was there and noticed that there wasn't an index for the opid (top level comment id for speeding up entire thread pulling) column. So I got some before numbers, added one, and ran some After tests. Heavily commented stories show a 50-150% pages-per-second speed increase in threaded views. Low hanging fruit FTW.
(Score: 2) by The Mighty Buzzard on Friday January 11 2019, @12:19PM
Okay, now that I can read English again, I think that's "working as intended" though permalinks having a page number in them in the first place may not be. When you supply a cid it should show you only that comment and any below it, thread-wise. If, and only if, those comments add up to more than your max comments per page setting, they should paginate based on the comments immediately below the one whose cid was supplied. Invalid page numbers should show the first page.
My rights don't end where your fear begins.