Hi, is there a way to use a postgres vector store (pgvector) as a docstore? All the data is actually already there.
Specifically, what I want to do, is use the data we already store in pgvector to build a QueryFusionRetriever, with a vector_retriever and a bm25retriever. In theory, I should be able to perform bm25 retrieval in the postgres database, but the bm25retriever can only be initilised with a docstore.
I also found out this sparse vector_store_query_mode, but I believe thats only for hybrid text search, so not what I am looking for.