It feels like there are an influx of "vector databases" right now, I haven't had a strong answer out of anyone on why you'd be better off using these over Redis which offers vector storage with similarity search in a battle-tested OSS solution.
Redis uses too much memory and supports only two NN algorithms FLAT (very slow) and HNSW if you start indexing millions of large vectors you will quickly understand the problem. That being said, many of these DBs are overcomplicated for most use cases. Redis HNSW will work for many use cases.
More to come. https://github.com/redisventures to keep up with our team