I want to know what possible retrievers I can use with SupabaseVectorStore as a vector store. also ParentDocumentRetriever, is it supported by supabase??

vector_store = SupabaseVectorStore(client=get_supabase_client(),
                                   embedding=get_embeddings(),
                                   table_name='documents',
                                   query_name='match_documents')
store = InMemoryStore()
child_splitter = RecursiveCharacterTextSplitter(chunk_size=400)
retriever = ParentDocumentRetriever(vectorstore=vector_store,
                                        docstore=store,
                                        child_splitter=child_splitter)

this code returns an empty list. in langchain ParentDocumentRetriever documentation Chroma vector store.