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858 lines
33 KiB
Python
858 lines
33 KiB
Python
"""Vector Store in Google Cloud BigQuery."""
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from __future__ import annotations
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import asyncio
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import json
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import logging
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import sys
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import uuid
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from datetime import datetime
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from functools import partial
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from threading import Lock, Thread
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from typing import Any, Callable, Dict, List, Optional, Tuple, Type
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import numpy as np
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from langchain_core.documents import Document
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from langchain_core.embeddings import Embeddings
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from langchain_core.vectorstores import VectorStore
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from langchain_community.vectorstores.utils import (
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DistanceStrategy,
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maximal_marginal_relevance,
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)
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DEFAULT_DISTANCE_STRATEGY = DistanceStrategy.EUCLIDEAN_DISTANCE
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DEFAULT_DOC_ID_COLUMN_NAME = "doc_id" # document id
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DEFAULT_TEXT_EMBEDDING_COLUMN_NAME = "text_embedding" # embeddings vectors
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DEFAULT_METADATA_COLUMN_NAME = "metadata" # document metadata
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DEFAULT_CONTENT_COLUMN_NAME = "content" # text content, do not rename
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DEFAULT_TOP_K = 4 # default number of documents returned from similarity search
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_MIN_INDEX_ROWS = 5000 # minimal number of rows for creating an index
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_INDEX_CHECK_PERIOD_SECONDS = 60 # Do not check for index more often that this.
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_vector_table_lock = Lock() # process-wide BigQueryVectorSearch table lock
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class BigQueryVectorSearch(VectorStore):
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"""Google Cloud BigQuery vector store.
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To use, you need the following packages installed:
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google-cloud-bigquery
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"""
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def __init__(
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self,
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embedding: Embeddings,
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project_id: str,
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dataset_name: str,
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table_name: str,
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location: str = "US",
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content_field: str = DEFAULT_CONTENT_COLUMN_NAME,
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metadata_field: str = DEFAULT_METADATA_COLUMN_NAME,
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text_embedding_field: str = DEFAULT_TEXT_EMBEDDING_COLUMN_NAME,
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doc_id_field: str = DEFAULT_DOC_ID_COLUMN_NAME,
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distance_strategy: DistanceStrategy = DEFAULT_DISTANCE_STRATEGY,
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credentials: Optional[Any] = None,
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):
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"""Constructor for BigQueryVectorSearch.
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Args:
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embedding (Embeddings): Text Embedding model to use.
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project_id (str): GCP project.
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dataset_name (str): BigQuery dataset to store documents and embeddings.
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table_name (str): BigQuery table name.
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location (str, optional): BigQuery region. Defaults to
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`US`(multi-region).
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content_field (str): Specifies the column to store the content.
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Defaults to `content`.
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metadata_field (str): Specifies the column to store the metadata.
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Defaults to `metadata`.
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text_embedding_field (str): Specifies the column to store
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the embeddings vector.
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Defaults to `text_embedding`.
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doc_id_field (str): Specifies the column to store the document id.
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Defaults to `doc_id`.
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distance_strategy (DistanceStrategy, optional):
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Determines the strategy employed for calculating
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the distance between vectors in the embedding space.
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Defaults to EUCLIDEAN_DISTANCE.
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Available options are:
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- COSINE: Measures the similarity between two vectors of an inner
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product space.
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- EUCLIDEAN_DISTANCE: Computes the Euclidean distance between
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two vectors. This metric considers the geometric distance in
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the vector space, and might be more suitable for embeddings
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that rely on spatial relationships. This is the default behavior
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credentials (Credentials, optional): Custom Google Cloud credentials
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to use. Defaults to None.
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"""
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try:
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from google.cloud import bigquery
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self.bq_client = bigquery.Client(
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project=project_id, location=location, credentials=credentials
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)
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except ModuleNotFoundError:
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raise ImportError(
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"Please, install or upgrade the google-cloud-bigquery library: "
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"pip install google-cloud-bigquery"
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)
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self._logger = logging.getLogger(__name__)
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self._creating_index = False
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self._have_index = False
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self.embedding_model = embedding
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self.project_id = project_id
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self.dataset_name = dataset_name
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self.table_name = table_name
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self.location = location
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self.content_field = content_field
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self.metadata_field = metadata_field
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self.text_embedding_field = text_embedding_field
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self.doc_id_field = doc_id_field
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self.distance_strategy = distance_strategy
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self._full_table_id = (
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f"{self.project_id}." f"{self.dataset_name}." f"{self.table_name}"
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)
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self._logger.debug("Using table `%s`", self.full_table_id)
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with _vector_table_lock:
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self.vectors_table = self._initialize_table()
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self._last_index_check = datetime.min
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self._initialize_vector_index()
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def _initialize_table(self) -> Any:
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"""Validates or creates the BigQuery table."""
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from google.cloud import bigquery
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table_ref = bigquery.TableReference.from_string(self._full_table_id)
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table = self.bq_client.create_table(table_ref, exists_ok=True)
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changed_schema = False
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schema = table.schema.copy()
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columns = {c.name: c for c in schema}
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if self.doc_id_field not in columns:
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changed_schema = True
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schema.append(
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bigquery.SchemaField(name=self.doc_id_field, field_type="STRING")
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)
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elif (
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columns[self.doc_id_field].field_type != "STRING"
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or columns[self.doc_id_field].mode == "REPEATED"
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):
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raise ValueError(f"Column {self.doc_id_field} must be of " "STRING type")
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if self.metadata_field not in columns:
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changed_schema = True
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schema.append(
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bigquery.SchemaField(name=self.metadata_field, field_type="JSON")
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)
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elif (
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columns[self.metadata_field].field_type not in ["JSON", "STRING"]
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or columns[self.metadata_field].mode == "REPEATED"
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):
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raise ValueError(
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f"Column {self.metadata_field} must be of STRING or JSON type"
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)
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if self.content_field not in columns:
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changed_schema = True
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schema.append(
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bigquery.SchemaField(name=self.content_field, field_type="STRING")
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)
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elif (
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columns[self.content_field].field_type != "STRING"
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or columns[self.content_field].mode == "REPEATED"
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):
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raise ValueError(f"Column {self.content_field} must be of " "STRING type")
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if self.text_embedding_field not in columns:
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changed_schema = True
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schema.append(
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bigquery.SchemaField(
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name=self.text_embedding_field,
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field_type="FLOAT64",
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mode="REPEATED",
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)
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)
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elif (
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columns[self.text_embedding_field].field_type not in ("FLOAT", "FLOAT64")
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or columns[self.text_embedding_field].mode != "REPEATED"
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):
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raise ValueError(
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f"Column {self.text_embedding_field} must be of " "ARRAY<FLOAT64> type"
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)
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if changed_schema:
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self._logger.debug("Updated table `%s` schema.", self.full_table_id)
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table.schema = schema
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table = self.bq_client.update_table(table, fields=["schema"])
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return table
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def _initialize_vector_index(self) -> Any:
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"""
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A vector index in BigQuery table enables efficient
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approximate vector search.
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"""
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from google.cloud import bigquery
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if self._have_index or self._creating_index:
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# Already have an index or in the process of creating one.
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return
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table = self.bq_client.get_table(self.vectors_table)
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if (table.num_rows or 0) < _MIN_INDEX_ROWS:
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# Not enough rows to create index.
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self._logger.debug("Not enough rows to create a vector index.")
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return
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if (
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datetime.utcnow() - self._last_index_check
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).total_seconds() < _INDEX_CHECK_PERIOD_SECONDS:
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return
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with _vector_table_lock:
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if self._creating_index or self._have_index:
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return
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self._last_index_check = datetime.utcnow()
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# Check if index exists, create if necessary
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check_query = (
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f"SELECT 1 FROM `{self.project_id}.{self.dataset_name}"
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".INFORMATION_SCHEMA.VECTOR_INDEXES` WHERE"
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f" table_name = '{self.table_name}'"
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)
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job = self.bq_client.query(
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check_query, api_method=bigquery.enums.QueryApiMethod.QUERY
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)
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if job.result().total_rows == 0:
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# Need to create an index. Make it in a separate thread.
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self._create_index_in_background()
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else:
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self._logger.debug("Vector index already exists.")
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self._have_index = True
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def _create_index_in_background(self): # type: ignore[no-untyped-def]
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if self._have_index or self._creating_index:
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# Already have an index or in the process of creating one.
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return
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self._creating_index = True
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self._logger.debug("Trying to create a vector index.")
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thread = Thread(target=self._create_index, daemon=True)
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thread.start()
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def _create_index(self): # type: ignore[no-untyped-def]
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from google.api_core.exceptions import ClientError
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table = self.bq_client.get_table(self.vectors_table)
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if (table.num_rows or 0) < _MIN_INDEX_ROWS:
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# Not enough rows to create index.
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return
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if self.distance_strategy == DistanceStrategy.EUCLIDEAN_DISTANCE:
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distance_type = "EUCLIDEAN"
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elif self.distance_strategy == DistanceStrategy.COSINE:
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distance_type = "COSINE"
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# Default to EUCLIDEAN_DISTANCE
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else:
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distance_type = "EUCLIDEAN"
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index_name = f"{self.table_name}_langchain_index"
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try:
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sql = f"""
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CREATE VECTOR INDEX IF NOT EXISTS
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`{index_name}`
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ON `{self.full_table_id}`({self.text_embedding_field})
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OPTIONS(distance_type="{distance_type}", index_type="IVF")
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"""
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self.bq_client.query(sql).result()
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self._have_index = True
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except ClientError as ex:
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self._logger.debug("Vector index creation failed (%s).", ex.args[0])
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finally:
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self._creating_index = False
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def _persist(self, data: Dict[str, Any]) -> None:
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"""Saves documents and embeddings to BigQuery."""
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from google.cloud import bigquery
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data_len = len(data[list(data.keys())[0]])
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if data_len == 0:
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return
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list_of_dicts = [dict(zip(data, t)) for t in zip(*data.values())]
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job_config = bigquery.LoadJobConfig()
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job_config.schema = self.vectors_table.schema
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job_config.schema_update_options = (
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bigquery.SchemaUpdateOption.ALLOW_FIELD_ADDITION
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)
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job_config.write_disposition = bigquery.WriteDisposition.WRITE_APPEND
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job = self.bq_client.load_table_from_json(
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list_of_dicts, self.vectors_table, job_config=job_config
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)
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job.result()
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@property
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def embeddings(self) -> Optional[Embeddings]:
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return self.embedding_model
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@property
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def full_table_id(self) -> str:
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return self._full_table_id
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def add_texts( # type: ignore[override]
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self,
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texts: List[str],
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metadatas: Optional[List[dict]] = None,
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**kwargs: Any,
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) -> List[str]:
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"""Run more texts through the embeddings and add to the vectorstore.
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Args:
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texts: List of strings to add to the vectorstore.
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metadatas: Optional list of metadata associated with the texts.
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Returns:
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List of ids from adding the texts into the vectorstore.
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"""
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embs = self.embedding_model.embed_documents(texts)
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return self.add_texts_with_embeddings(texts, embs, metadatas, **kwargs)
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def add_texts_with_embeddings(
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self,
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texts: List[str],
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embs: List[List[float]],
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metadatas: Optional[List[dict]] = None,
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**kwargs: Any,
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) -> List[str]:
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"""Run more texts through the embeddings and add to the vectorstore.
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Args:
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texts: List of strings to add to the vectorstore.
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embs: List of lists of floats with text embeddings for texts.
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metadatas: Optional list of metadata associated with the texts.
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Returns:
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List of ids from adding the texts into the vectorstore.
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"""
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ids = [uuid.uuid4().hex for _ in texts]
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values_dict: Dict[str, List[Any]] = {
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self.content_field: texts,
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self.doc_id_field: ids,
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}
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if not metadatas:
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metadatas = []
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len_diff = len(ids) - len(metadatas)
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add_meta = [None for _ in range(0, len_diff)]
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metadatas = [m if m is not None else {} for m in metadatas + add_meta]
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values_dict[self.metadata_field] = metadatas
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values_dict[self.text_embedding_field] = embs
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self._persist(values_dict)
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return ids
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def get_documents(
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self, ids: Optional[List[str]] = None, filter: Optional[Dict[str, Any]] = None
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) -> List[Document]:
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"""Search documents by their ids or metadata values.
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Args:
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ids: List of ids of documents to retrieve from the vectorstore.
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filter: Filter on metadata properties, e.g.
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{
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"str_property": "foo",
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"int_property": 123
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}
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Returns:
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List of ids from adding the texts into the vectorstore.
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"""
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if ids and len(ids) > 0:
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from google.cloud import bigquery
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job_config = bigquery.QueryJobConfig(
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query_parameters=[
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bigquery.ArrayQueryParameter("ids", "STRING", ids),
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]
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)
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id_expr = f"{self.doc_id_field} IN UNNEST(@ids)"
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else:
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job_config = None
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id_expr = "TRUE"
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if filter:
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filter_expressions = []
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for i in filter.items():
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if isinstance(i[1], float):
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expr = (
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"ABS(CAST(JSON_VALUE("
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f"`{self.metadata_field}`,'$.{i[0]}') "
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f"AS FLOAT64) - {i[1]}) "
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f"<= {sys.float_info.epsilon}"
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)
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else:
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val = str(i[1]).replace('"', '\\"')
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expr = (
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f"JSON_VALUE(`{self.metadata_field}`,'$.{i[0]}')" f' = "{val}"'
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)
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filter_expressions.append(expr)
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filter_expression_str = " AND ".join(filter_expressions)
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where_filter_expr = f" AND ({filter_expression_str})"
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else:
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where_filter_expr = ""
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job = self.bq_client.query(
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f"""
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SELECT * FROM `{self.full_table_id}` WHERE {id_expr}
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{where_filter_expr}
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""",
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job_config=job_config,
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)
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docs: List[Document] = []
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for row in job:
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metadata = None
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if self.metadata_field:
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metadata = row[self.metadata_field]
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if metadata:
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metadata = json.loads(metadata)
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else:
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metadata = {}
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metadata["__id"] = row[self.doc_id_field]
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doc = Document(page_content=row[self.content_field], metadata=metadata)
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docs.append(doc)
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return docs
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def delete(self, ids: Optional[List[str]] = None, **kwargs: Any) -> Optional[bool]:
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"""Delete by vector ID or other criteria.
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Args:
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ids: List of ids to delete.
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**kwargs: Other keyword arguments that subclasses might use.
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Returns:
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Optional[bool]: True if deletion is successful,
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False otherwise, None if not implemented.
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"""
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if not ids or len(ids) == 0:
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return True
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from google.cloud import bigquery
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job_config = bigquery.QueryJobConfig(
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query_parameters=[
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bigquery.ArrayQueryParameter("ids", "STRING", ids),
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]
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)
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self.bq_client.query(
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f"""
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DELETE FROM `{self.full_table_id}` WHERE {self.doc_id_field}
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IN UNNEST(@ids)
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""",
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job_config=job_config,
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).result()
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return True
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|
async def adelete(
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self, ids: Optional[List[str]] = None, **kwargs: Any
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) -> Optional[bool]:
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"""Delete by vector ID or other criteria.
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|
Args:
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ids: List of ids to delete.
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**kwargs: Other keyword arguments that subclasses might use.
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Returns:
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Optional[bool]: True if deletion is successful,
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False otherwise, None if not implemented.
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"""
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return await asyncio.get_running_loop().run_in_executor(
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None, partial(self.delete, **kwargs), ids
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)
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|
def _search_with_score_and_embeddings_by_vector(
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|
self,
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embedding: List[float],
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k: int = DEFAULT_TOP_K,
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filter: Optional[Dict[str, Any]] = None,
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brute_force: bool = False,
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fraction_lists_to_search: Optional[float] = None,
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) -> List[Tuple[Document, List[float], float]]:
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|
from google.cloud import bigquery
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|
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# Create an index if no index exists.
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if not self._have_index and not self._creating_index:
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self._initialize_vector_index()
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# Prepare filter
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filter_expr = "TRUE"
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if filter:
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filter_expressions = []
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|
for i in filter.items():
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if isinstance(i[1], float):
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expr = (
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"ABS(CAST(JSON_VALUE("
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f"base.`{self.metadata_field}`,'$.{i[0]}') "
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f"AS FLOAT64) - {i[1]}) "
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f"<= {sys.float_info.epsilon}"
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)
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else:
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val = str(i[1]).replace('"', '\\"')
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expr = (
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f"JSON_VALUE(base.`{self.metadata_field}`,'$.{i[0]}')"
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f' = "{val}"'
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)
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filter_expressions.append(expr)
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filter_expression_str = " AND ".join(filter_expressions)
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filter_expr += f" AND ({filter_expression_str})"
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# Configure and run a query job.
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|
job_config = bigquery.QueryJobConfig(
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query_parameters=[
|
|
bigquery.ArrayQueryParameter("v", "FLOAT64", embedding),
|
|
],
|
|
use_query_cache=False,
|
|
priority=bigquery.QueryPriority.BATCH,
|
|
)
|
|
if self.distance_strategy == DistanceStrategy.EUCLIDEAN_DISTANCE:
|
|
distance_type = "EUCLIDEAN"
|
|
elif self.distance_strategy == DistanceStrategy.COSINE:
|
|
distance_type = "COSINE"
|
|
# Default to EUCLIDEAN_DISTANCE
|
|
else:
|
|
distance_type = "EUCLIDEAN"
|
|
if brute_force:
|
|
options_string = ",options => '{\"use_brute_force\":true}'"
|
|
elif fraction_lists_to_search:
|
|
if fraction_lists_to_search == 0 or fraction_lists_to_search >= 1.0:
|
|
raise ValueError(
|
|
"`fraction_lists_to_search` must be between " "0.0 and 1.0"
|
|
)
|
|
options_string = (
|
|
',options => \'{"fraction_lists_to_search":'
|
|
f"{fraction_lists_to_search}}}'"
|
|
)
|
|
else:
|
|
options_string = ""
|
|
query = f"""
|
|
SELECT
|
|
base.*,
|
|
distance AS _vector_search_distance
|
|
FROM VECTOR_SEARCH(
|
|
TABLE `{self.full_table_id}`,
|
|
"{self.text_embedding_field}",
|
|
(SELECT @v AS {self.text_embedding_field}),
|
|
distance_type => "{distance_type}",
|
|
top_k => {k}
|
|
{options_string}
|
|
)
|
|
WHERE {filter_expr}
|
|
LIMIT {k}
|
|
"""
|
|
document_tuples: List[Tuple[Document, List[float], float]] = []
|
|
# TODO(vladkol): Use jobCreationMode=JOB_CREATION_OPTIONAL when available.
|
|
job = self.bq_client.query(
|
|
query, job_config=job_config, api_method=bigquery.enums.QueryApiMethod.QUERY
|
|
)
|
|
# Process job results.
|
|
for row in job:
|
|
metadata = row[self.metadata_field]
|
|
if metadata:
|
|
metadata = json.loads(metadata)
|
|
else:
|
|
metadata = {}
|
|
metadata["__id"] = row[self.doc_id_field]
|
|
metadata["__job_id"] = job.job_id
|
|
doc = Document(page_content=row[self.content_field], metadata=metadata)
|
|
document_tuples.append(
|
|
(doc, row[self.text_embedding_field], row["_vector_search_distance"])
|
|
)
|
|
return document_tuples
|
|
|
|
def similarity_search_with_score_by_vector(
|
|
self,
|
|
embedding: List[float],
|
|
k: int = DEFAULT_TOP_K,
|
|
filter: Optional[Dict[str, Any]] = None,
|
|
brute_force: bool = False,
|
|
fraction_lists_to_search: Optional[float] = None,
|
|
**kwargs: Any,
|
|
) -> List[Tuple[Document, float]]:
|
|
"""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: Filter on metadata properties, e.g.
|
|
{
|
|
"str_property": "foo",
|
|
"int_property": 123
|
|
}
|
|
brute_force: Whether to use brute force search. Defaults to False.
|
|
fraction_lists_to_search: Optional percentage of lists to search,
|
|
must be in range 0.0 and 1.0, exclusive.
|
|
If Node, uses service's default which is 0.05.
|
|
|
|
Returns:
|
|
List of Documents most similar to the query vector with distance.
|
|
"""
|
|
del kwargs
|
|
document_tuples = self._search_with_score_and_embeddings_by_vector(
|
|
embedding, k, filter, brute_force, fraction_lists_to_search
|
|
)
|
|
return [(doc, distance) for doc, _, distance in document_tuples]
|
|
|
|
def similarity_search_by_vector(
|
|
self,
|
|
embedding: List[float],
|
|
k: int = DEFAULT_TOP_K,
|
|
filter: Optional[Dict[str, Any]] = None,
|
|
brute_force: bool = False,
|
|
fraction_lists_to_search: Optional[float] = 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: Filter on metadata properties, e.g.
|
|
{
|
|
"str_property": "foo",
|
|
"int_property": 123
|
|
}
|
|
brute_force: Whether to use brute force search. Defaults to False.
|
|
fraction_lists_to_search: Optional percentage of lists to search,
|
|
must be in range 0.0 and 1.0, exclusive.
|
|
If Node, uses service's default which is 0.05.
|
|
|
|
Returns:
|
|
List of Documents most similar to the query vector.
|
|
"""
|
|
tuples = self.similarity_search_with_score_by_vector(
|
|
embedding, k, filter, brute_force, fraction_lists_to_search, **kwargs
|
|
)
|
|
return [i[0] for i in tuples]
|
|
|
|
def similarity_search_with_score(
|
|
self,
|
|
query: str,
|
|
k: int = DEFAULT_TOP_K,
|
|
filter: Optional[Dict[str, Any]] = None,
|
|
brute_force: bool = False,
|
|
fraction_lists_to_search: Optional[float] = None,
|
|
**kwargs: Any,
|
|
) -> List[Tuple[Document, float]]:
|
|
"""Run similarity search with score.
|
|
|
|
Args:
|
|
query: search query text.
|
|
k: Number of Documents to return. Defaults to 4.
|
|
filter: Filter on metadata properties, e.g.
|
|
{
|
|
"str_property": "foo",
|
|
"int_property": 123
|
|
}
|
|
brute_force: Whether to use brute force search. Defaults to False.
|
|
fraction_lists_to_search: Optional percentage of lists to search,
|
|
must be in range 0.0 and 1.0, exclusive.
|
|
If Node, uses service's default which is 0.05.
|
|
|
|
Returns:
|
|
List of Documents most similar to the query vector, with similarity scores.
|
|
"""
|
|
emb = self.embedding_model.embed_query(query) # type: ignore
|
|
return self.similarity_search_with_score_by_vector(
|
|
emb, k, filter, brute_force, fraction_lists_to_search, **kwargs
|
|
)
|
|
|
|
def similarity_search(
|
|
self,
|
|
query: str,
|
|
k: int = DEFAULT_TOP_K,
|
|
filter: Optional[Dict[str, Any]] = None,
|
|
brute_force: bool = False,
|
|
fraction_lists_to_search: Optional[float] = None,
|
|
**kwargs: Any,
|
|
) -> List[Document]:
|
|
"""Run similarity search.
|
|
|
|
Args:
|
|
query: search query text.
|
|
k: Number of Documents to return. Defaults to 4.
|
|
filter: Filter on metadata properties, e.g.
|
|
{
|
|
"str_property": "foo",
|
|
"int_property": 123
|
|
}
|
|
brute_force: Whether to use brute force search. Defaults to False.
|
|
fraction_lists_to_search: Optional percentage of lists to search,
|
|
must be in range 0.0 and 1.0, exclusive.
|
|
If Node, uses service's default which is 0.05.
|
|
|
|
Returns:
|
|
List of Documents most similar to the query vector.
|
|
"""
|
|
tuples = self.similarity_search_with_score(
|
|
query, k, filter, brute_force, fraction_lists_to_search, **kwargs
|
|
)
|
|
return [i[0] for i in tuples]
|
|
|
|
def _select_relevance_score_fn(self) -> Callable[[float], float]:
|
|
if self.distance_strategy == DistanceStrategy.COSINE:
|
|
return BigQueryVectorSearch._cosine_relevance_score_fn
|
|
else:
|
|
raise ValueError(
|
|
"Relevance score is not supported "
|
|
f"for `{self.distance_strategy}` distance."
|
|
)
|
|
|
|
def max_marginal_relevance_search(
|
|
self,
|
|
query: str,
|
|
k: int = DEFAULT_TOP_K,
|
|
fetch_k: int = DEFAULT_TOP_K * 5,
|
|
lambda_mult: float = 0.5,
|
|
filter: Optional[Dict[str, Any]] = None,
|
|
brute_force: bool = False,
|
|
fraction_lists_to_search: Optional[float] = None,
|
|
**kwargs: Any,
|
|
) -> List[Document]:
|
|
"""Return docs selected using the maximal marginal relevance.
|
|
|
|
Maximal marginal relevance optimizes for similarity to query AND diversity
|
|
among selected documents.
|
|
|
|
Args:
|
|
query: search query text.
|
|
k: Number of Documents to return. Defaults to 4.
|
|
fetch_k: Number of Documents to fetch to pass to MMR algorithm.
|
|
lambda_mult: Number between 0 and 1 that determines the degree
|
|
of diversity among the results with 0 corresponding
|
|
to maximum diversity and 1 to minimum diversity.
|
|
Defaults to 0.5.
|
|
filter: Filter on metadata properties, e.g.
|
|
{
|
|
"str_property": "foo",
|
|
"int_property": 123
|
|
}
|
|
brute_force: Whether to use brute force search. Defaults to False.
|
|
fraction_lists_to_search: Optional percentage of lists to search,
|
|
must be in range 0.0 and 1.0, exclusive.
|
|
If Node, uses service's default which is 0.05.
|
|
Returns:
|
|
List of Documents selected by maximal marginal relevance.
|
|
"""
|
|
query_embedding = self.embedding_model.embed_query( # type: ignore
|
|
query
|
|
)
|
|
doc_tuples = self._search_with_score_and_embeddings_by_vector(
|
|
query_embedding, fetch_k, filter, brute_force, fraction_lists_to_search
|
|
)
|
|
doc_embeddings = [d[1] for d in doc_tuples]
|
|
mmr_doc_indexes = maximal_marginal_relevance(
|
|
np.array(query_embedding), doc_embeddings, lambda_mult=lambda_mult, k=k
|
|
)
|
|
return [doc_tuples[i][0] for i in mmr_doc_indexes]
|
|
|
|
def max_marginal_relevance_search_by_vector(
|
|
self,
|
|
embedding: List[float],
|
|
k: int = DEFAULT_TOP_K,
|
|
fetch_k: int = DEFAULT_TOP_K * 5,
|
|
lambda_mult: float = 0.5,
|
|
filter: Optional[Dict[str, Any]] = None,
|
|
brute_force: bool = False,
|
|
fraction_lists_to_search: Optional[float] = None,
|
|
**kwargs: Any,
|
|
) -> List[Document]:
|
|
"""Return docs selected using the maximal marginal relevance.
|
|
|
|
Maximal marginal relevance optimizes for similarity to query AND diversity
|
|
among selected documents.
|
|
|
|
Args:
|
|
embedding: Embedding to look up documents similar to.
|
|
k: Number of Documents to return. Defaults to 4.
|
|
fetch_k: Number of Documents to fetch to pass to MMR algorithm.
|
|
lambda_mult: Number between 0 and 1 that determines the degree
|
|
of diversity among the results with 0 corresponding
|
|
to maximum diversity and 1 to minimum diversity.
|
|
Defaults to 0.5.
|
|
filter: Filter on metadata properties, e.g.
|
|
{
|
|
"str_property": "foo",
|
|
"int_property": 123
|
|
}
|
|
brute_force: Whether to use brute force search. Defaults to False.
|
|
fraction_lists_to_search: Optional percentage of lists to search,
|
|
must be in range 0.0 and 1.0, exclusive.
|
|
If Node, uses service's default which is 0.05.
|
|
Returns:
|
|
List of Documents selected by maximal marginal relevance.
|
|
"""
|
|
doc_tuples = self._search_with_score_and_embeddings_by_vector(
|
|
embedding, fetch_k, filter, brute_force, fraction_lists_to_search
|
|
)
|
|
doc_embeddings = [d[1] for d in doc_tuples]
|
|
mmr_doc_indexes = maximal_marginal_relevance(
|
|
np.array(embedding), doc_embeddings, lambda_mult=lambda_mult, k=k
|
|
)
|
|
return [doc_tuples[i][0] for i in mmr_doc_indexes]
|
|
|
|
async def amax_marginal_relevance_search(
|
|
self,
|
|
query: str,
|
|
k: int = DEFAULT_TOP_K,
|
|
fetch_k: int = DEFAULT_TOP_K * 5,
|
|
lambda_mult: float = 0.5,
|
|
filter: Optional[Dict[str, Any]] = None,
|
|
brute_force: bool = False,
|
|
fraction_lists_to_search: Optional[float] = None,
|
|
**kwargs: Any,
|
|
) -> List[Document]:
|
|
"""Return docs selected using the maximal marginal relevance."""
|
|
|
|
func = partial(
|
|
self.max_marginal_relevance_search,
|
|
query,
|
|
k=k,
|
|
fetch_k=fetch_k,
|
|
lambda_mult=lambda_mult,
|
|
filter=filter,
|
|
brute_force=brute_force,
|
|
fraction_lists_to_search=fraction_lists_to_search,
|
|
**kwargs,
|
|
)
|
|
return await asyncio.get_event_loop().run_in_executor(None, func)
|
|
|
|
async def amax_marginal_relevance_search_by_vector(
|
|
self,
|
|
embedding: List[float],
|
|
k: int = DEFAULT_TOP_K,
|
|
fetch_k: int = DEFAULT_TOP_K * 5,
|
|
lambda_mult: float = 0.5,
|
|
filter: Optional[Dict[str, Any]] = None,
|
|
brute_force: bool = False,
|
|
fraction_lists_to_search: Optional[float] = None,
|
|
**kwargs: Any,
|
|
) -> List[Document]:
|
|
"""Return docs selected using the maximal marginal relevance."""
|
|
return await asyncio.get_running_loop().run_in_executor(
|
|
None,
|
|
partial(self.max_marginal_relevance_search_by_vector, **kwargs),
|
|
embedding,
|
|
k,
|
|
fetch_k,
|
|
lambda_mult,
|
|
filter,
|
|
brute_force,
|
|
fraction_lists_to_search,
|
|
)
|
|
|
|
@classmethod
|
|
def from_texts(
|
|
cls: Type["BigQueryVectorSearch"],
|
|
texts: List[str],
|
|
embedding: Embeddings,
|
|
metadatas: Optional[List[dict]] = None,
|
|
**kwargs: Any,
|
|
) -> "BigQueryVectorSearch":
|
|
"""Return VectorStore initialized from texts and embeddings."""
|
|
vs_obj = BigQueryVectorSearch(embedding=embedding, **kwargs)
|
|
vs_obj.add_texts(texts, metadatas)
|
|
return vs_obj
|
|
|
|
def explore_job_stats(self, job_id: str) -> Dict:
|
|
"""Return the statistics for a single job execution.
|
|
|
|
Args:
|
|
job_id: The BigQuery Job id.
|
|
|
|
Returns:
|
|
A dictionary of job statistics for a given job.
|
|
"""
|
|
return self.bq_client.get_job(job_id)._properties["statistics"]
|