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MyScale

MyScale is a cloud-based database optimized for AI applications and solutions, built on the open-source ClickHouse.

This notebook shows how to use functionality related to the MyScale vector database.

Setting up environmentsโ€‹

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

We want to use OpenAIEmbeddings so we have to get the OpenAI API Key.

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:")

There are two ways to set up parameters for myscale index.

  1. Environment Variables

    Before you run the app, please set the environment variable with export: export MYSCALE_HOST='<your-endpoints-url>' MYSCALE_PORT=<your-endpoints-port> MYSCALE_USERNAME=<your-username> MYSCALE_PASSWORD=<your-password> ...

    You can easily find your account, password and other info on our SaaS. For details please refer to this document

    Every attributes under MyScaleSettings can be set with prefix MYSCALE_ and is case insensitive.

  2. Create MyScaleSettings object with parameters

```python
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 Reference:TextLoader
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%|โ–ˆโ–ˆโ–ˆโ–ˆโ–ˆโ–ˆโ–ˆโ–ˆโ–ˆโ–ˆ| 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 youโ€™re at it, pass the Disclose Act so Americans can know who is funding our elections. 

Tonight, Iโ€™d like to honor someone who has dedicated his life to serve this country: Justice Stephen Breyerโ€”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 nationโ€™s top legal minds, who will continue Justice Breyerโ€™s legacy of excellence.

Get connection info and data schemaโ€‹

print(str(docsearch))

Filteringโ€‹

You can have direct access to myscale SQL where statement. You can write WHERE clause following standard SQL.

NOTE: Please be aware of SQL injection, this interface must not be directly called by end-user.

If you customized your column_map under your setting, you search with filter like this:

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)
API Reference:TextLoader | MyScale
Inserting data...: 100%|โ–ˆโ–ˆโ–ˆโ–ˆโ–ˆโ–ˆโ–ˆโ–ˆโ–ˆโ–ˆ| 42/42 [00:15<00:00,  2.68it/s]

Similarity search with scoreโ€‹

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 Iโ€™m taking robus...

Deleting your dataโ€‹

You can either drop the table with .drop() method or partially delete your data with .delete() method.

# 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 Iโ€™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()

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