Thanks! Macroexpanded:

Database “sharding” came from Ultima Online? - https://news.ycombinator.com/item?id=35479553 - April 2023 (89 comments)

Database “sharding” came from Ultima Online? (2009) - https://news.ycombinator.com/item?id=34694397 - Feb 2023 (1 comment)

Database “sharding” came from Ultima Online? (2009) - https://news.ycombinator.com/item?id=23438399 - June 2020 (172 comments)

Database “sharding” came from Ultima Online? (2009) - https://news.ycombinator.com/item?id=17926566 - Sept 2018 (1 comment)

Database “sharding” came from Ultima Online? (2009) - https://news.ycombinator.com/item?id=16343939 - Feb 2018 (1 comment)

Did the term 'sharding' start with Ultima Online? - https://news.ycombinator.com/item?id=425765 - Jan 2009 (3 comments)

As for https://news.ycombinator.com/item?id=36848605 - I've added it to https://news.ycombinator.com/highlights. Thanks!

Dan, is there a way to automatically add related older discussions to the top of a new item, in a similar way to submitting the same URL within a certain time will take you to the existing discussion rather than create a new one?

HN does that if the URLs are identical (or nearly identical) and a submission has had significant attention in the last year or so. But for related stories that have different URLs, it's a harder problem. Our intention is to build support for this that will be community-curated. Someday!

It's definitely possible clientside; Refind Hacker News browser extension does it at the bottom of the page.