import logging # We configure how logging messages should be displayed and which log level should be used before importing Haystack. # Example log message: # INFO - haystack.utils.preprocessing - Converting data/tutorial1/218_Olenna_Tyrell.txt # Default log level in basicConfig is WARNING so the explicit parameter is not necessary but can be changed easily: logging.basicConfig(format="%(levelname)s - %(name)s - %(message)s", level=logging.WARNING) logging.getLogger("haystack").setLevel(logging.INFO) from haystack.document_stores import FAISSDocumentStore, MilvusDocumentStore from haystack.utils import clean_wiki_text, print_answers, launch_milvus, convert_files_to_docs, fetch_archive_from_http from haystack.nodes import FARMReader, EmbeddingRetriever def tutorial6_better_retrieval_via_embedding_retrieval(): # OPTION 1: FAISS is a library for efficient similarity search on a cluster of dense vectors. # The FAISSDocumentStore uses a SQL(SQLite in-memory be default) document store under-the-hood # to store the document text and other meta data. The vector embeddings of the text are # indexed on a FAISS Index that later is queried for searching answers. # The default flavour of FAISSDocumentStore is "Flat" but can also be set to "HNSW" for # faster search at the expense of some accuracy. Just set the faiss_index_factor_str argument in the constructor. # For more info on which suits your use case: https://github.com/facebookresearch/faiss/wiki/Guidelines-to-choose-an-index # Do not forget to install its dependencies with `pip install farm-haystack[faiss]` document_store = FAISSDocumentStore(faiss_index_factory_str="Flat") # OPTION2: Milvus is an open source database library that is also optimized for vector similarity searches like FAISS. # Like FAISS it has both a "Flat" and "HNSW" mode but it outperforms FAISS when it comes to dynamic data management. # It does require a little more setup, however, as it is run through Docker and requires the setup of some config files. # See https://milvus.io/docs/v1.0.0/milvus_docker-cpu.md # Do not forget to install its dependencies with `pip install farm-haystack[milvus]` # launch_milvus() # document_store = MilvusDocumentStore() # ## Preprocessing of documents # Let's first get some documents that we want to query doc_dir = "data/tutorial6" s3_url = "https://s3.eu-central-1.amazonaws.com/deepset.ai-farm-qa/datasets/documents/wiki_gameofthrones_txt6.zip" fetch_archive_from_http(url=s3_url, output_dir=doc_dir) # convert files to dicts containing documents that can be indexed to our datastore docs = convert_files_to_docs(dir_path=doc_dir, clean_func=clean_wiki_text, split_paragraphs=True) # Now, let's write the docs to our DB. document_store.write_documents(docs) ### Retriever retriever = EmbeddingRetriever( document_store=document_store, embedding_model="sentence-transformers/multi-qa-mpnet-base-dot-v1", model_format="sentence_transformers", ) # Important: # Now that we initialized the Retriever, we need to call update_embeddings() to iterate over all # previously indexed documents and update their embedding representation. # While this can be a time consuming operation (depending on the corpus size), it only needs to be done once. # At query time, we only need to embed the query and compare it to the existing document embeddings, which is very fast. document_store.update_embeddings(retriever) ### Reader # Load a local model or any of the QA models on # Hugging Face's model hub (https://huggingface.co/models) reader = FARMReader(model_name_or_path="deepset/roberta-base-squad2", use_gpu=True) ### Pipeline from haystack.pipelines import ExtractiveQAPipeline pipe = ExtractiveQAPipeline(reader, retriever) ## VoilĂ ! Ask a question! prediction = pipe.run( query="Who is the father of Arya Stark?", params={"Retriever": {"top_k": 10}, "Reader": {"top_k": 5}} ) # prediction = pipe.run(query="Who created the Dothraki vocabulary?", params={"Reader": {"top_k": 5}}) # prediction = pipe.run(query="Who is the sister of Sansa?", params={"Reader": {"top_k": 5}}) print_answers(prediction, details="minimum") if __name__ == "__main__": tutorial6_better_retrieval_via_embedding_retrieval() # This Haystack script was made with love by deepset in Berlin, Germany # Haystack: https://github.com/deepset-ai/haystack # deepset: https://deepset.ai/