popular Vector Indexing - HNSW, IVF
vector DBs exist for one fundamental reason: to do approximate nearest neighbor (ANN) search fast at scale. Everything else — filtering, hybrid search, persistence, distributed sharding — is built around that core operation.
If you remember nothing else: vector DB = ANN index + a query layer + persistence + ops.
3. Indexing algorithms the heart of the topic
7. Production concerns — the FDE lens