This is the coolest relay that exists:
nostr.com/nevent1qqsqqqqpznc… (https://nostr.com/nevent1qqsqqqqpznc3km5vytyds9x7z9z8adg4nx6mhyptkw0gcuchwn8aa4qpyfmhxue69uhkummnw3ez6an9wf5kv6t9vsh8wetvd3hhyer9wghxuet59sqwr6)
The PoW requirements are adjusted to keep the database size constant, and all previous notes with less proof of work than the current threshold are excluded.
https://nitter.moomoo.me/fiatjaf/status/1658876464790372360#m