I switched from Memcached to Redis 10 years ago because I had a situation where I needed to cache lookups of (x, y) but needed to invalidate (x, *), something t

I switched from Memcached to Redis 10 years ago because I had a situation where I needed to cache lookups of (x, y) but needed to invalidate (x, *), something that is trivial with Redis hashes, but extremely difficult in memcached.