Redis
Vector databasesVector search inside Redis — similarity search alongside the cache you already run.
Redis, the in-memory data store, includes vector similarity search. For teams already running Redis as a cache or queue, that means adding retrieval without adding a system — and getting very low query latency from memory.
It is best suited to working sets that fit comfortably in RAM, where its speed is hard to beat.
Where it's ideally used
A fit when you already run Redis and want low-latency vector search without operating a separate database.
Where it doesn't fit
Holding everything in memory gets expensive for large vector sets — a disk-based store scales more cheaply.