- 精确和近似最近邻搜索
- L2 距离、内积和余弦距离
Kinetica)。
使用前需要一个 Kinetica 实例,可按照此处的说明轻松部署——安装说明。
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# Pip install necessary package
pip install -qU langchain-kinetica
OpenAIEmbeddings,因此需要获取 OpenAI API 密钥。
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import getpass
import os
from langchain_openai import OpenAIEmbeddings
if "OPENAI_API_KEY" not in os.environ:
os.environ["OPENAI_API_KEY"] = getpass.getpass("OpenAI API Key:")
embeddings = OpenAIEmbeddings(model="text-embedding-3-large")
.env 文件中设置:
KINETICA_URL:数据库连接 URL(例如http://localhost:9191)KINETICA_USER:数据库用户名KINETICA_PASSWD:安全密码
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# Kinetica needs the connection to the database.
# Set these environment variables:
from gpudb import GPUdb
from langchain_kinetica import KineticaSettings, KineticaVectorstore
kdbc = GPUdb.get_connection()
k_config = KineticaSettings(kdbc=kdbc)
k_config
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2026-02-02 21:28:34.745 INFO [GPUdb] Connected to Kinetica! (host=http://localhost:19191 api=7.2.3.3 server=7.2.3.5)
KineticaSettings(kdbc=<gpudb.gpudb.GPUdb object at 0x1170ae270>, database='langchain', table='langchain_kinetica_embeddings', metric='l2')
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from uuid import uuid4
from langchain_core.documents import Document
document_1 = Document(
page_content="I had chocolate chip pancakes and scrambled eggs for"
" breakfast this morning.",
metadata={"source": "tweet"},
)
document_2 = Document(
page_content="The weather forecast for tomorrow is cloudy and overcast"
", with a high of 62 degrees.",
metadata={"source": "news"},
)
document_3 = Document(
page_content="Building an exciting new project with LangChain - come check it out!",
metadata={"source": "tweet"},
)
document_4 = Document(
page_content="Robbers broke into the city bank and stole $1 million in cash.",
metadata={"source": "news"},
)
document_5 = Document(
page_content="Wow! That was an amazing movie. I can't wait to see it again.",
metadata={"source": "tweet"},
)
document_6 = Document(
page_content="Is the new iPhone worth the price? Read this review to find out.",
metadata={"source": "website"},
)
document_7 = Document(
page_content="The top 10 soccer players in the world right now.",
metadata={"source": "website"},
)
document_8 = Document(
page_content="LangGraph is the best framework for building stateful"
", agentic applications!",
metadata={"source": "tweet"},
)
document_9 = Document(
page_content="The stock market is down 500 points today due to"
" fears of a recession.",
metadata={"source": "news"},
)
document_10 = Document(
page_content="I have a bad feeling I am going to get deleted :(",
metadata={"source": "tweet"},
)
documents = [
document_1,
document_2,
document_3,
document_4,
document_5,
document_6,
document_7,
document_8,
document_9,
document_10,
]
uuids = [str(uuid4()) for _ in range(len(documents))]
uuids
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['ddad79f1-141d-44f6-8f50-72e5c0f1ee16',
'10819fa9-794b-4fde-934a-aabd453781c8',
'3ce641d5-8c6b-4dcb-90fe-a3c19b3132ff',
'9db5c865-389f-481c-aea2-440b8437e22c',
'74dd4d80-a371-4c41-8254-7981d375274d',
'74d7571e-f8c5-4001-9979-e99996ec2ce5',
'3a3eb718-f2b9-4186-8c2e-34a1e18ebb3b',
'59a88b08-f8c6-4cf5-b485-9485a4a8ffd0',
'd84ad1c8-ec01-4d13-b61a-ef4b08abb485',
'c9ab8f4f-e566-465f-a85d-ee05780714ea']
使用欧氏距离进行相似度搜索(默认)
Kinetica 模块将尝试使用集合名称创建一张表。因此,请确保集合名称唯一,且用户具有创建表的权限。Copy
COLLECTION_NAME = "langchain_example"
vectorstore = KineticaVectorstore(
config=k_config,
embedding_function=embeddings,
collection_name=COLLECTION_NAME,
pre_delete_collection=True,
)
vectorstore.add_documents(documents=documents, ids=uuids)
print()
print("Similarity Search")
results = vectorstore.similarity_search(
"LangChain provides abstractions to make working with LLMs easy",
k=2,
filter={"source": "tweet"},
)
for res in results:
print(f"* {res.page_content} [{res.metadata}]")
print()
print("Similarity search with score")
results = vectorstore.similarity_search_with_score(
"Will it be hot tomorrow?", k=1, emb_filter={"source": "news"}
)
for res, score in results:
print(f"* [SIM={score:3f}] {res.page_content} [{res.metadata}]")
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Similarity Search
* Building an exciting new project with LangChain - come check it out! [{'source': 'tweet'}]
* LangGraph is the best framework for building stateful, agentic applications! [{'source': 'tweet'}]
Similarity search with score
* [SIM=0.945353] The weather forecast for tomorrow is cloudy and overcast, with a high of 62 degrees. [{'source': 'news'}]
使用向量存储
添加文档
上面,我们从头创建了一个向量存储。然而,很多时候我们希望使用已有的向量存储。 为此,我们可以直接初始化它。Copy
vectorstore = KineticaVectorstore(
config=k_config,
embedding_function=embeddings,
collection_name=COLLECTION_NAME,
)
# We can add documents to the existing vectorstore.
vectorstore.add_documents([Document(page_content="foo")])
docs_with_score = vectorstore.similarity_search_with_score("foo")
print(f"First result: {docs_with_score[0]}")
print(f"Second result: {docs_with_score[1]}")
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First result: (Document(metadata={}, page_content='foo'), 0.0014664357295259833)
Second result: (Document(metadata={'source': 'tweet'}, page_content='Building an exciting new project with LangChain - come check it out!'), 1.260981559753418)
覆盖向量存储
如果您已有一个集合,可以通过from_documents 并设置 pre_delete_collection = True 来覆盖它
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vectorstore = KineticaVectorstore.from_documents(
documents=documents,
embedding=embeddings,
collection_name=COLLECTION_NAME,
config=k_config,
pre_delete_collection=True,
)
docs_with_score = vectorstore.similarity_search_with_score("foo")
docs_with_score[0]
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(Document(metadata={'source': 'tweet'}, page_content='Building an exciting new project with LangChain - come check it out!'),
1.2609236240386963)
将向量存储用作检索器
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from langchain_core.vectorstores.base import VectorStoreRetriever
retriever: VectorStoreRetriever = vectorstore.as_retriever()
retriever
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VectorStoreRetriever(tags=['KineticaVectorstore', 'OpenAIEmbeddings'], vectorstore=<langchain_kinetica.vectorstores.KineticaVectorstore object at 0x1139cfaa0>, search_kwargs={})
通过 MCP 将这些文档连接 到 Claude、VSCode 等,获取实时答案。

