There are different approaches for turning vectors into terms which you can then simply index with something like Elasticsearch. There are papers by the Walmart

There are different approaches for turning vectors into terms which you can then simply index with something like Elasticsearch. There are papers by the Walmart and Jet.com teams that describe different approaches, starting with both binarised vectors as well as full float vectors. Not saying that this is what Pinecone is using, so it will be interesting to read their follow-up.