Comment by samus

> He doesn't point to a single thing that pg_vector doesn't do or doesn't do well. He just complains it hard to do.

He very clearly complains that IVFFlat indexes have to be periodically rebuilt, that HNSW has high overhead (both during inserts and rebuilds) and that the query planner is not particularly good at optimizing queries involving this kind of indexes. None of this is a problem if the dataset is puny enough, but deadly if you want to scale up without investing significant engineering.