I propose that the B-Tree index item (bottom-up index deletion, "Allow btree index additions to remove expired index entries to prevent page splits") link back to the documentation for those that want to drill down:
https://www.postgresql.org/docs/14/btree-implementation.html#BTREE-DELETION The same approach was used for the Postgres 13 B-Tree deduplication release note item (same page from the docs, even). I understand that it's kind of hard to get the point of the feature across within the confines of the release notes, which have a very wide audience. I believe that the practical take-away for more experienced users should be something like "significantly ameliorates write-amplification problems in indexes with non-HOT updates". But that's quite a mouthful. Having a hyperlink to the docs seems like a sensible compromise. I really just want experienced users to be able to make the connection between this feature and well-publicized problems with Postgres index bloat/VACUUM. Thanks -- Peter Geoghegan
