Constrained vector search

[pablogranolabar]

Various vector databases have support for additional metadata such as dates, but langchain doesn't appear to support any type of joins to facilitate constrained vector search, to for example only retrieve documents within a specific date range. Any thoughts on how this would be best implemented, I can submit a PR given a bit of guidance.

[willsmithorg]

Pinecone definitely supports metadata filtering. Good video explanation : https://www.youtube.com/watch?v=tn_Y19oB5bs .

Pinecone's similarity_search looks like this, looks to me like it supports a filter.

def similarity_search(
self,
query: str,
k: int = 4,
filter: Optional[dict] = None,
namespace: Optional[str] = None,
**kwargs: Any,
) -> List[Document]: