Source code for langchain_community.vectorstores.timescalevector

"""VectorStore wrapper around a Postgres-TimescaleVector database."""
from __future__ import annotations

import enum
import logging
import uuid
from datetime import timedelta
from typing import (
    TYPE_CHECKING,
    Any,
    Callable,
    Dict,
    Iterable,
    List,
    Optional,
    Tuple,
    Type,
    Union,
)

from langchain_core.documents import Document
from langchain_core.embeddings import Embeddings
from langchain_core.utils import get_from_dict_or_env
from langchain_core.vectorstores import VectorStore

from langchain_community.vectorstores.utils import DistanceStrategy

if TYPE_CHECKING:
    from timescale_vector import Predicates


DEFAULT_DISTANCE_STRATEGY = DistanceStrategy.COSINE

ADA_TOKEN_COUNT = 1536

_LANGCHAIN_DEFAULT_COLLECTION_NAME = "langchain_store"


[docs]class TimescaleVector(VectorStore): """Timescale Postgres vector store To use, you should have the ``timescale_vector`` python package installed. Args: service_url: Service url on timescale cloud. embedding: Any embedding function implementing `langchain.embeddings.base.Embeddings` interface. collection_name: The name of the collection to use. (default: langchain_store) This will become the table name used for the collection. distance_strategy: The distance strategy to use. (default: COSINE) pre_delete_collection: If True, will delete the collection if it exists. (default: False). Useful for testing. Example: .. code-block:: python from langchain_community.vectorstores import TimescaleVector from langchain_community.embeddings.openai import OpenAIEmbeddings SERVICE_URL = "postgres://tsdbadmin:<password>@<id>.tsdb.cloud.timescale.com:<port>/tsdb?sslmode=require" COLLECTION_NAME = "state_of_the_union_test" embeddings = OpenAIEmbeddings() vectorestore = TimescaleVector.from_documents( embedding=embeddings, documents=docs, collection_name=COLLECTION_NAME, service_url=SERVICE_URL, ) """ # noqa: E501
[docs] def __init__( self, service_url: str, embedding: Embeddings, collection_name: str = _LANGCHAIN_DEFAULT_COLLECTION_NAME, num_dimensions: int = ADA_TOKEN_COUNT, distance_strategy: DistanceStrategy = DEFAULT_DISTANCE_STRATEGY, pre_delete_collection: bool = False, logger: Optional[logging.Logger] = None, relevance_score_fn: Optional[Callable[[float], float]] = None, time_partition_interval: Optional[timedelta] = None, **kwargs: Any, ) -> None: try: from timescale_vector import client except ImportError: raise ImportError( "Could not import timescale_vector python package. " "Please install it with `pip install timescale-vector`." ) self.service_url = service_url self.embedding = embedding self.collection_name = collection_name self.num_dimensions = num_dimensions self._distance_strategy = distance_strategy self.pre_delete_collection = pre_delete_collection self.logger = logger or logging.getLogger(__name__) self.override_relevance_score_fn = relevance_score_fn self._time_partition_interval = time_partition_interval self.sync_client = client.Sync( self.service_url, self.collection_name, self.num_dimensions, self._distance_strategy.value.lower(), time_partition_interval=self._time_partition_interval, **kwargs, ) self.async_client = client.Async( self.service_url, self.collection_name, self.num_dimensions, self._distance_strategy.value.lower(), time_partition_interval=self._time_partition_interval, **kwargs, ) self.__post_init__()
def __post_init__( self, ) -> None: """ Initialize the store. """ self.sync_client.create_tables() if self.pre_delete_collection: self.sync_client.delete_all() @property def embeddings(self) -> Embeddings: return self.embedding
[docs] def drop_tables(self) -> None: self.sync_client.drop_table()
@classmethod def __from( cls, texts: List[str], embeddings: List[List[float]], embedding: Embeddings, metadatas: Optional[List[dict]] = None, ids: Optional[List[str]] = None, collection_name: str = _LANGCHAIN_DEFAULT_COLLECTION_NAME, distance_strategy: DistanceStrategy = DEFAULT_DISTANCE_STRATEGY, service_url: Optional[str] = None, pre_delete_collection: bool = False, **kwargs: Any, ) -> TimescaleVector: num_dimensions = len(embeddings[0]) if ids is None: ids = [str(uuid.uuid4()) for _ in texts] if not metadatas: metadatas = [{} for _ in texts] if service_url is None: service_url = cls.get_service_url(kwargs) store = cls( service_url=service_url, num_dimensions=num_dimensions, collection_name=collection_name, embedding=embedding, distance_strategy=distance_strategy, pre_delete_collection=pre_delete_collection, **kwargs, ) store.add_embeddings( texts=texts, embeddings=embeddings, metadatas=metadatas, ids=ids, **kwargs ) return store @classmethod async def __afrom( cls, texts: List[str], embeddings: List[List[float]], embedding: Embeddings, metadatas: Optional[List[dict]] = None, ids: Optional[List[str]] = None, collection_name: str = _LANGCHAIN_DEFAULT_COLLECTION_NAME, distance_strategy: DistanceStrategy = DEFAULT_DISTANCE_STRATEGY, service_url: Optional[str] = None, pre_delete_collection: bool = False, **kwargs: Any, ) -> TimescaleVector: num_dimensions = len(embeddings[0]) if ids is None: ids = [str(uuid.uuid4()) for _ in texts] if not metadatas: metadatas = [{} for _ in texts] if service_url is None: service_url = cls.get_service_url(kwargs) store = cls( service_url=service_url, num_dimensions=num_dimensions, collection_name=collection_name, embedding=embedding, distance_strategy=distance_strategy, pre_delete_collection=pre_delete_collection, **kwargs, ) await store.aadd_embeddings( texts=texts, embeddings=embeddings, metadatas=metadatas, ids=ids, **kwargs ) return store
[docs] def add_embeddings( self, texts: Iterable[str], embeddings: List[List[float]], metadatas: Optional[List[dict]] = None, ids: Optional[List[str]] = None, **kwargs: Any, ) -> List[str]: """Add embeddings to the vectorstore. Args: texts: Iterable of strings to add to the vectorstore. embeddings: List of list of embedding vectors. metadatas: List of metadatas associated with the texts. kwargs: vectorstore specific parameters """ if ids is None: ids = [str(uuid.uuid4()) for _ in texts] if not metadatas: metadatas = [{} for _ in texts] records = list(zip(ids, metadatas, texts, embeddings)) self.sync_client.upsert(records) return ids
[docs] async def aadd_embeddings( self, texts: Iterable[str], embeddings: List[List[float]], metadatas: Optional[List[dict]] = None, ids: Optional[List[str]] = None, **kwargs: Any, ) -> List[str]: """Add embeddings to the vectorstore. Args: texts: Iterable of strings to add to the vectorstore. embeddings: List of list of embedding vectors. metadatas: List of metadatas associated with the texts. kwargs: vectorstore specific parameters """ if ids is None: ids = [str(uuid.uuid4()) for _ in texts] if not metadatas: metadatas = [{} for _ in texts] records = list(zip(ids, metadatas, texts, embeddings)) await self.async_client.upsert(records) return ids
[docs] def add_texts( self, texts: Iterable[str], metadatas: Optional[List[dict]] = None, ids: Optional[List[str]] = None, **kwargs: Any, ) -> List[str]: """Run more texts through the embeddings and add to the vectorstore. Args: texts: Iterable of strings to add to the vectorstore. metadatas: Optional list of metadatas associated with the texts. kwargs: vectorstore specific parameters Returns: List of ids from adding the texts into the vectorstore. """ embeddings = self.embedding.embed_documents(list(texts)) return self.add_embeddings( texts=texts, embeddings=embeddings, metadatas=metadatas, ids=ids, **kwargs )
[docs] async def aadd_texts( self, texts: Iterable[str], metadatas: Optional[List[dict]] = None, ids: Optional[List[str]] = None, **kwargs: Any, ) -> List[str]: """Run more texts through the embeddings and add to the vectorstore. Args: texts: Iterable of strings to add to the vectorstore. metadatas: Optional list of metadatas associated with the texts. kwargs: vectorstore specific parameters Returns: List of ids from adding the texts into the vectorstore. """ embeddings = self.embedding.embed_documents(list(texts)) return await self.aadd_embeddings( texts=texts, embeddings=embeddings, metadatas=metadatas, ids=ids, **kwargs )
def _embed_query(self, query: str) -> Optional[List[float]]: # an empty query should not be embedded if query is None or query == "" or query.isspace(): return None else: return self.embedding.embed_query(query)
[docs] def similarity_search_with_score( self, query: str, k: int = 4, filter: Optional[Union[dict, list]] = None, predicates: Optional[Predicates] = None, **kwargs: Any, ) -> List[Tuple[Document, float]]: """Return docs most similar to query. Args: query: Text to look up documents similar to. k: Number of Documents to return. Defaults to 4. filter (Optional[Dict[str, str]]): Filter by metadata. Defaults to None. Returns: List of Documents most similar to the query and score for each """ embedding = self._embed_query(query) docs = self.similarity_search_with_score_by_vector( embedding=embedding, k=k, filter=filter, predicates=predicates, **kwargs, ) return docs
[docs] async def asimilarity_search_with_score( self, query: str, k: int = 4, filter: Optional[Union[dict, list]] = None, predicates: Optional[Predicates] = None, **kwargs: Any, ) -> List[Tuple[Document, float]]: """Return docs most similar to query. Args: query: Text to look up documents similar to. k: Number of Documents to return. Defaults to 4. filter (Optional[Dict[str, str]]): Filter by metadata. Defaults to None. Returns: List of Documents most similar to the query and score for each """ embedding = self._embed_query(query) return await self.asimilarity_search_with_score_by_vector( embedding=embedding, k=k, filter=filter, predicates=predicates, **kwargs, )
[docs] def date_to_range_filter(self, **kwargs: Any) -> Any: constructor_args = { key: kwargs[key] for key in [ "start_date", "end_date", "time_delta", "start_inclusive", "end_inclusive", ] if key in kwargs } if not constructor_args or len(constructor_args) == 0: return None try: from timescale_vector import client except ImportError: raise ImportError( "Could not import timescale_vector python package. " "Please install it with `pip install timescale-vector`." ) return client.UUIDTimeRange(**constructor_args)
[docs] def similarity_search_with_score_by_vector( self, embedding: Optional[List[float]], k: int = 4, filter: Optional[Union[dict, list]] = None, predicates: Optional[Predicates] = None, **kwargs: Any, ) -> List[Tuple[Document, float]]: try: from timescale_vector import client except ImportError: raise ImportError( "Could not import timescale_vector python package. " "Please install it with `pip install timescale-vector`." ) results = self.sync_client.search( embedding, limit=k, filter=filter, predicates=predicates, uuid_time_filter=self.date_to_range_filter(**kwargs), ) docs = [ ( Document( page_content=result[client.SEARCH_RESULT_CONTENTS_IDX], metadata=result[client.SEARCH_RESULT_METADATA_IDX], ), result[client.SEARCH_RESULT_DISTANCE_IDX], ) for result in results ] return docs
[docs] async def asimilarity_search_with_score_by_vector( self, embedding: Optional[List[float]], k: int = 4, filter: Optional[Union[dict, list]] = None, predicates: Optional[Predicates] = None, **kwargs: Any, ) -> List[Tuple[Document, float]]: try: from timescale_vector import client except ImportError: raise ImportError( "Could not import timescale_vector python package. " "Please install it with `pip install timescale-vector`." ) results = await self.async_client.search( embedding, limit=k, filter=filter, predicates=predicates, uuid_time_filter=self.date_to_range_filter(**kwargs), ) docs = [ ( Document( page_content=result[client.SEARCH_RESULT_CONTENTS_IDX], metadata=result[client.SEARCH_RESULT_METADATA_IDX], ), result[client.SEARCH_RESULT_DISTANCE_IDX], ) for result in results ] return docs
[docs] def similarity_search_by_vector( self, embedding: Optional[List[float]], k: int = 4, filter: Optional[Union[dict, list]] = None, predicates: Optional[Predicates] = None, **kwargs: Any, ) -> List[Document]: """Return docs most similar to embedding vector. Args: embedding: Embedding to look up documents similar to. k: Number of Documents to return. Defaults to 4. filter (Optional[Dict[str, str]]): Filter by metadata. Defaults to None. Returns: List of Documents most similar to the query vector. """ docs_and_scores = self.similarity_search_with_score_by_vector( embedding=embedding, k=k, filter=filter, predicates=predicates, **kwargs ) return [doc for doc, _ in docs_and_scores]
[docs] async def asimilarity_search_by_vector( self, embedding: Optional[List[float]], k: int = 4, filter: Optional[Union[dict, list]] = None, predicates: Optional[Predicates] = None, **kwargs: Any, ) -> List[Document]: """Return docs most similar to embedding vector. Args: embedding: Embedding to look up documents similar to. k: Number of Documents to return. Defaults to 4. filter (Optional[Dict[str, str]]): Filter by metadata. Defaults to None. Returns: List of Documents most similar to the query vector. """ docs_and_scores = await self.asimilarity_search_with_score_by_vector( embedding=embedding, k=k, filter=filter, predicates=predicates, **kwargs ) return [doc for doc, _ in docs_and_scores]
[docs] @classmethod def from_texts( cls: Type[TimescaleVector], texts: List[str], embedding: Embeddings, metadatas: Optional[List[dict]] = None, collection_name: str = _LANGCHAIN_DEFAULT_COLLECTION_NAME, distance_strategy: DistanceStrategy = DEFAULT_DISTANCE_STRATEGY, ids: Optional[List[str]] = None, pre_delete_collection: bool = False, **kwargs: Any, ) -> TimescaleVector: """ Return VectorStore initialized from texts and embeddings. Postgres connection string is required "Either pass it as a parameter or set the TIMESCALE_SERVICE_URL environment variable. """ embeddings = embedding.embed_documents(list(texts)) return cls.__from( texts, embeddings, embedding, metadatas=metadatas, ids=ids, collection_name=collection_name, distance_strategy=distance_strategy, pre_delete_collection=pre_delete_collection, **kwargs, )
[docs] @classmethod async def afrom_texts( cls: Type[TimescaleVector], texts: List[str], embedding: Embeddings, metadatas: Optional[List[dict]] = None, collection_name: str = _LANGCHAIN_DEFAULT_COLLECTION_NAME, distance_strategy: DistanceStrategy = DEFAULT_DISTANCE_STRATEGY, ids: Optional[List[str]] = None, pre_delete_collection: bool = False, **kwargs: Any, ) -> TimescaleVector: """ Return VectorStore initialized from texts and embeddings. Postgres connection string is required "Either pass it as a parameter or set the TIMESCALE_SERVICE_URL environment variable. """ embeddings = embedding.embed_documents(list(texts)) return await cls.__afrom( texts, embeddings, embedding, metadatas=metadatas, ids=ids, collection_name=collection_name, distance_strategy=distance_strategy, pre_delete_collection=pre_delete_collection, **kwargs, )
[docs] @classmethod def from_embeddings( cls, text_embeddings: List[Tuple[str, List[float]]], embedding: Embeddings, metadatas: Optional[List[dict]] = None, collection_name: str = _LANGCHAIN_DEFAULT_COLLECTION_NAME, distance_strategy: DistanceStrategy = DEFAULT_DISTANCE_STRATEGY, ids: Optional[List[str]] = None, pre_delete_collection: bool = False, **kwargs: Any, ) -> TimescaleVector: """Construct TimescaleVector wrapper from raw documents and pre- generated embeddings. Return VectorStore initialized from documents and embeddings. Postgres connection string is required "Either pass it as a parameter or set the TIMESCALE_SERVICE_URL environment variable. Example: .. code-block:: python from langchain_community.vectorstores import TimescaleVector from langchain_community.embeddings import OpenAIEmbeddings embeddings = OpenAIEmbeddings() text_embeddings = embeddings.embed_documents(texts) text_embedding_pairs = list(zip(texts, text_embeddings)) tvs = TimescaleVector.from_embeddings(text_embedding_pairs, embeddings) """ texts = [t[0] for t in text_embeddings] embeddings = [t[1] for t in text_embeddings] return cls.__from( texts, embeddings, embedding, metadatas=metadatas, ids=ids, collection_name=collection_name, distance_strategy=distance_strategy, pre_delete_collection=pre_delete_collection, **kwargs, )
[docs] @classmethod async def afrom_embeddings( cls, text_embeddings: List[Tuple[str, List[float]]], embedding: Embeddings, metadatas: Optional[List[dict]] = None, collection_name: str = _LANGCHAIN_DEFAULT_COLLECTION_NAME, distance_strategy: DistanceStrategy = DEFAULT_DISTANCE_STRATEGY, ids: Optional[List[str]] = None, pre_delete_collection: bool = False, **kwargs: Any, ) -> TimescaleVector: """Construct TimescaleVector wrapper from raw documents and pre- generated embeddings. Return VectorStore initialized from documents and embeddings. Postgres connection string is required "Either pass it as a parameter or set the TIMESCALE_SERVICE_URL environment variable. Example: .. code-block:: python from langchain_community.vectorstores import TimescaleVector from langchain_community.embeddings import OpenAIEmbeddings embeddings = OpenAIEmbeddings() text_embeddings = embeddings.embed_documents(texts) text_embedding_pairs = list(zip(texts, text_embeddings)) tvs = TimescaleVector.from_embeddings(text_embedding_pairs, embeddings) """ texts = [t[0] for t in text_embeddings] embeddings = [t[1] for t in text_embeddings] return await cls.__afrom( texts, embeddings, embedding, metadatas=metadatas, ids=ids, collection_name=collection_name, distance_strategy=distance_strategy, pre_delete_collection=pre_delete_collection, **kwargs, )
[docs] @classmethod def from_existing_index( cls: Type[TimescaleVector], embedding: Embeddings, collection_name: str = _LANGCHAIN_DEFAULT_COLLECTION_NAME, distance_strategy: DistanceStrategy = DEFAULT_DISTANCE_STRATEGY, pre_delete_collection: bool = False, **kwargs: Any, ) -> TimescaleVector: """ Get instance of an existing TimescaleVector store.This method will return the instance of the store without inserting any new embeddings """ service_url = cls.get_service_url(kwargs) store = cls( service_url=service_url, collection_name=collection_name, embedding=embedding, distance_strategy=distance_strategy, pre_delete_collection=pre_delete_collection, ) return store
[docs] @classmethod def get_service_url(cls, kwargs: Dict[str, Any]) -> str: service_url: str = get_from_dict_or_env( data=kwargs, key="service_url", env_key="TIMESCALE_SERVICE_URL", ) if not service_url: raise ValueError( "Postgres connection string is required" "Either pass it as a parameter" "or set the TIMESCALE_SERVICE_URL environment variable." ) return service_url
[docs] @classmethod def service_url_from_db_params( cls, host: str, port: int, database: str, user: str, password: str, ) -> str: """Return connection string from database parameters.""" return f"postgresql://{user}:{password}@{host}:{port}/{database}"
def _select_relevance_score_fn(self) -> Callable[[float], float]: """ The 'correct' relevance function may differ depending on a few things, including: - the distance / similarity metric used by the VectorStore - the scale of your embeddings (OpenAI's are unit normed. Many others are not!) - embedding dimensionality - etc. """ if self.override_relevance_score_fn is not None: return self.override_relevance_score_fn # Default strategy is to rely on distance strategy provided # in vectorstore constructor if self._distance_strategy == DistanceStrategy.COSINE: return self._cosine_relevance_score_fn elif self._distance_strategy == DistanceStrategy.EUCLIDEAN_DISTANCE: return self._euclidean_relevance_score_fn elif self._distance_strategy == DistanceStrategy.MAX_INNER_PRODUCT: return self._max_inner_product_relevance_score_fn else: raise ValueError( "No supported normalization function" f" for distance_strategy of {self._distance_strategy}." "Consider providing relevance_score_fn to TimescaleVector constructor." )
[docs] def delete(self, ids: Optional[List[str]] = None, **kwargs: Any) -> Optional[bool]: """Delete by vector ID or other criteria. Args: ids: List of ids to delete. **kwargs: Other keyword arguments that subclasses might use. Returns: Optional[bool]: True if deletion is successful, False otherwise, None if not implemented. """ if ids is None: raise ValueError("No ids provided to delete.") self.sync_client.delete_by_ids(ids) return True
# todo should this be part of delete|()?
[docs] def delete_by_metadata( self, filter: Union[Dict[str, str], List[Dict[str, str]]], **kwargs: Any ) -> Optional[bool]: """Delete by vector ID or other criteria. Args: ids: List of ids to delete. **kwargs: Other keyword arguments that subclasses might use. Returns: Optional[bool]: True if deletion is successful, False otherwise, None if not implemented. """ self.sync_client.delete_by_metadata(filter) return True
class IndexType(str, enum.Enum): """Enumerator for the supported Index types""" TIMESCALE_VECTOR = "tsv" PGVECTOR_IVFFLAT = "ivfflat" PGVECTOR_HNSW = "hnsw" DEFAULT_INDEX_TYPE = IndexType.TIMESCALE_VECTOR
[docs] def create_index( self, index_type: Union[IndexType, str] = DEFAULT_INDEX_TYPE, **kwargs: Any ) -> None: try: from timescale_vector import client except ImportError: raise ImportError( "Could not import timescale_vector python package. " "Please install it with `pip install timescale-vector`." ) index_type = ( index_type.value if isinstance(index_type, self.IndexType) else index_type ) if index_type == self.IndexType.PGVECTOR_IVFFLAT.value: self.sync_client.create_embedding_index(client.IvfflatIndex(**kwargs)) if index_type == self.IndexType.PGVECTOR_HNSW.value: self.sync_client.create_embedding_index(client.HNSWIndex(**kwargs)) if index_type == self.IndexType.TIMESCALE_VECTOR.value: self.sync_client.create_embedding_index( client.TimescaleVectorIndex(**kwargs) )
[docs] def drop_index(self) -> None: self.sync_client.drop_embedding_index()