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MyScale

MyScale 是一个基于开源 ClickHouse 构建的、专为人工智能应用和解决方案优化的云数据库。

此笔记本展示了如何使用与MyScale向量数据库相关功能。

设置环境​

%pip install --upgrade --quiet  clickhouse-connect langchain-community

我们需要使用 OpenAIEmbeddings，因此必须获取 OpenAI API 密钥。

import getpass
import os

if "OPENAI_API_KEY" not in os.environ:
    os.environ["OPENAI_API_KEY"] = getpass.getpass("OpenAI API Key:")
if "OPENAI_API_BASE" not in os.environ:
    os.environ["OPENAI_API_BASE"] = getpass.getpass("OpenAI Base:")
if "MYSCALE_HOST" not in os.environ:
    os.environ["MYSCALE_HOST"] = getpass.getpass("MyScale Host:")
if "MYSCALE_PORT" not in os.environ:
    os.environ["MYSCALE_PORT"] = getpass.getpass("MyScale Port:")
if "MYSCALE_USERNAME" not in os.environ:
    os.environ["MYSCALE_USERNAME"] = getpass.getpass("MyScale Username:")
if "MYSCALE_PASSWORD" not in os.environ:
    os.environ["MYSCALE_PASSWORD"] = getpass.getpass("MyScale Password:")

有两条途径可以设置 myscale 索引的参数。

  1. 环境变量

    在运行应用程序之前，请设置环境变量，使用以下代码：export: export MYSCALE_HOST='<your-endpoints-url>' MYSCALE_PORT=<your-endpoints-port> MYSCALE_USERNAME=<your-username> MYSCALE_PASSWORD=<your-password> ...

    您可以在我们的SaaS平台上轻松找到您的账户、密码及其他信息。详情请参考本文档

    在 MyScaleSettings 下的每个属性都可以使用前缀 MYSCALE_ 进行设置，且不区分大小写。

  2. 使用参数创建 MyScaleSettings 对象

    from langchain_community.vectorstores import MyScale, MyScaleSettings
    config = MyScaleSetting(host="<your-backend-url>", port=8443, ...)
    index = MyScale(embedding_function, config)
    index.add_documents(...)
from langchain_community.document_loaders import TextLoader
from langchain_community.vectorstores import MyScale
from langchain_openai import OpenAIEmbeddings
from langchain_text_splitters import CharacterTextSplitter
from langchain_community.document_loaders import TextLoader

loader = TextLoader("../../how_to/state_of_the_union.txt")
documents = loader.load()
text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=0)
docs = text_splitter.split_documents(documents)

embeddings = OpenAIEmbeddings()
API 参考:文本加载器
for d in docs:
    d.metadata = {"some": "metadata"}
docsearch = MyScale.from_documents(docs, embeddings)

query = "What did the president say about Ketanji Brown Jackson"
docs = docsearch.similarity_search(query)
Inserting data...: 100%|██████████| 42/42 [00:15<00:00,  2.66it/s]
print(docs[0].page_content)
Tonight. I call on the Senate to: Pass the Freedom to Vote Act. Pass the John Lewis Voting Rights Act. And while you’re at it, pass the Disclose Act so Americans can know who is funding our elections. 

Tonight, I’d like to honor someone who has dedicated his life to serve this country: Justice Stephen Breyer—an Army veteran, Constitutional scholar, and retiring Justice of the United States Supreme Court. Justice Breyer, thank you for your service. 

One of the most serious constitutional responsibilities a President has is nominating someone to serve on the United States Supreme Court. 

And I did that 4 days ago, when I nominated Circuit Court of Appeals Judge Ketanji Brown Jackson. One of our nation’s top legal minds, who will continue Justice Breyer’s legacy of excellence.

获取连接信息和数据模式​

print(str(docsearch))

过滤​

您可以直接访问myscale SQL的where语句。您可以按照标准SQL编写WHERE子句。

注意：请意识到 SQL 注入的风险，此接口不得直接由最终用户调用。

如果您在设置中自定义了您的 column_map，您可以使用如下过滤器进行搜索：

from langchain_community.document_loaders import TextLoader
from langchain_community.vectorstores import MyScale

loader = TextLoader("../../how_to/state_of_the_union.txt")
documents = loader.load()
text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=0)
docs = text_splitter.split_documents(documents)

embeddings = OpenAIEmbeddings()

for i, d in enumerate(docs):
    d.metadata = {"doc_id": i}

docsearch = MyScale.from_documents(docs, embeddings)
Inserting data...: 100%|██████████| 42/42 [00:15<00:00,  2.68it/s]

相似性搜索（带分数）​

The returned distance score is cosine distance. Therefore, a lower score is better.

meta = docsearch.metadata_column
output = docsearch.similarity_search_with_relevance_scores(
    "What did the president say about Ketanji Brown Jackson?",
    k=4,
    where_str=f"{meta}.doc_id<10",
)
for d, dist in output:
    print(dist, d.metadata, d.page_content[:20] + "...")
0.229655921459198 {'doc_id': 0} Madam Speaker, Madam...
0.24506962299346924 {'doc_id': 8} And so many families...
0.24786919355392456 {'doc_id': 1} Groups of citizens b...
0.24875116348266602 {'doc_id': 6} And I’m taking robus...

删除您的数据​

您可以使用 .drop() 方法删除整个表，或使用 .delete() 方法部分删除您的数据。

# use directly a `where_str` to delete
docsearch.delete(where_str=f"{docsearch.metadata_column}.doc_id < 5")
meta = docsearch.metadata_column
output = docsearch.similarity_search_with_relevance_scores(
    "What did the president say about Ketanji Brown Jackson?",
    k=4,
    where_str=f"{meta}.doc_id<10",
)
for d, dist in output:
    print(dist, d.metadata, d.page_content[:20] + "...")
0.24506962299346924 {'doc_id': 8} And so many families...
0.24875116348266602 {'doc_id': 6} And I’m taking robus...
0.26027143001556396 {'doc_id': 7} We see the unity amo...
0.26390212774276733 {'doc_id': 9} And unlike the $2 Tr...
docsearch.drop()