Hi,
With PG16's 19d8e230, we got rid of BRIN's blocking of HOT updates,
but I just realized that we failed to update the README.HOT document
with this new exception for summarizing indexes.
Attached a patch that updates that document, detailing the related rationale.
I'm not sure if such internal documentation is relevant for
backpatching, but I also don't think it woudl hurt to have this
included in the REL_16_STABLE branch.
Kind regards,
Matthias van de Meent
Neon (https://neon.tech/)