> ## Documentation Index
> Fetch the complete documentation index at: https://langchain.idochub.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Alibaba Cloud MaxCompute

> [Alibaba Cloud MaxCompute](https://www.alibabacloud.com/product/maxcompute) (previously known as ODPS) is a general purpose, fully managed, multi-tenancy data processing platform for large-scale data warehousing. MaxCompute supports various data importing solutions and distributed computing models, enabling users to effectively query massive datasets, reduce production costs, and ensure data security.

The `MaxComputeLoader` lets you execute a MaxCompute SQL query and loads the results as one document per row.

```python theme={null}
%pip install -qU  pyodps
```

```output theme={null}
Collecting pyodps
  Downloading pyodps-0.11.4.post0-cp39-cp39-macosx_10_9_universal2.whl (2.0 MB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 2.0/2.0 MB 1.7 MB/s eta 0:00:0000:0100:010m
Requirement already satisfied: charset-normalizer>=2 in /Users/newboy/anaconda3/envs/langchain/lib/python3.9/site-packages (from pyodps) (3.1.0)
Requirement already satisfied: urllib3<2.0,>=1.26.0 in /Users/newboy/anaconda3/envs/langchain/lib/python3.9/site-packages (from pyodps) (1.26.15)
Requirement already satisfied: idna>=2.5 in /Users/newboy/anaconda3/envs/langchain/lib/python3.9/site-packages (from pyodps) (3.4)
Requirement already satisfied: certifi>=2017.4.17 in /Users/newboy/anaconda3/envs/langchain/lib/python3.9/site-packages (from pyodps) (2023.5.7)
Installing collected packages: pyodps
Successfully installed pyodps-0.11.4.post0
```

## Basic Usage

To instantiate the loader you'll need a SQL query to execute, your MaxCompute endpoint and project name, and your access ID and secret access key. The access ID and secret access key can either be passed in direct via the `access_id` and `secret_access_key` parameters or they can be set as environment variables `MAX_COMPUTE_ACCESS_ID` and `MAX_COMPUTE_SECRET_ACCESS_KEY`.

```python theme={null}
from langchain_community.document_loaders import MaxComputeLoader
```

```python theme={null}
base_query = """
SELECT *
FROM (
    SELECT 1 AS id, 'content1' AS content, 'meta_info1' AS meta_info
    UNION ALL
    SELECT 2 AS id, 'content2' AS content, 'meta_info2' AS meta_info
    UNION ALL
    SELECT 3 AS id, 'content3' AS content, 'meta_info3' AS meta_info
) mydata;
"""
```

```python theme={null}
endpoint = "<ENDPOINT>"
project = "<PROJECT>"
ACCESS_ID = "<ACCESS ID>"
SECRET_ACCESS_KEY = "<SECRET ACCESS KEY>"
```

```python theme={null}
loader = MaxComputeLoader.from_params(
    base_query,
    endpoint,
    project,
    access_id=ACCESS_ID,
    secret_access_key=SECRET_ACCESS_KEY,
)
data = loader.load()
```

```python theme={null}
print(data)
```

```output theme={null}
[Document(page_content='id: 1\ncontent: content1\nmeta_info: meta_info1', metadata={}), Document(page_content='id: 2\ncontent: content2\nmeta_info: meta_info2', metadata={}), Document(page_content='id: 3\ncontent: content3\nmeta_info: meta_info3', metadata={})]
```

```python theme={null}
print(data[0].page_content)
```

```output theme={null}
id: 1
content: content1
meta_info: meta_info1
```

```python theme={null}
print(data[0].metadata)
```

```output theme={null}
{}
```

## Specifying Which Columns are Content vs Metadata

You can configure which subset of columns should be loaded as the contents of the Document and which as the metadata using the `page_content_columns` and `metadata_columns` parameters.

```python theme={null}
loader = MaxComputeLoader.from_params(
    base_query,
    endpoint,
    project,
    page_content_columns=["content"],  # Specify Document page content
    metadata_columns=["id", "meta_info"],  # Specify Document metadata
    access_id=ACCESS_ID,
    secret_access_key=SECRET_ACCESS_KEY,
)
data = loader.load()
```

```python theme={null}
print(data[0].page_content)
```

```output theme={null}
content: content1
```

```python theme={null}
print(data[0].metadata)
```

```output theme={null}
{'id': 1, 'meta_info': 'meta_info1'}
```