If you'd like an alternate approach, txtai can store content in Postgres. This approach stores metadata/fields in the database and builds a Faiss/HNSW index alongside. The idea is to lean on two mature projects vs having to rewrite a full vector index implementation.
https://neuml.hashnode.dev/external-database-integration
https://github.com/neuml/txtai
Disclaimer: I'm the primary author of txtai