> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-mintlify-8a08bda2.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

> Provides a read-only table-like interface to Apache Hudi tables in Amazon S3.

# hudi

Provides a read-only table-like interface to Apache [Hudi](https://hudi.apache.org/) tables in Amazon S3.

<h2 id="syntax">
  Syntax
</h2>

```sql theme={null}
hudi(url [,aws_access_key_id, aws_secret_access_key] [,format] [,structure] [,compression] [,extra_credentials])
```

<h2 id="arguments">
  Arguments
</h2>

| Argument                                     | Description                                                                                                                                                                                                                                                                                                                                                                                 |
| -------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `url`                                        | Bucket url with the path to an existing Hudi table in S3.                                                                                                                                                                                                                                                                                                                                   |
| `aws_access_key_id`, `aws_secret_access_key` | Long-term credentials for the [AWS](https://aws.amazon.com/) account user.  You can use these to authenticate your requests. These parameters are optional. If credentials are not specified, they are used from the ClickHouse configuration. For more information see [Using S3 for Data Storage](/reference/engines/table-engines/mergetree-family/mergetree#table_engine-mergetree-s3). |
| `format`                                     | The [format](/reference/formats) of the file.                                                                                                                                                                                                                                                                                                                                               |
| `structure`                                  | Structure of the table. Format `'column1_name column1_type, column2_name column2_type, ...'`.                                                                                                                                                                                                                                                                                               |
| `compression`                                | Parameter is optional. Supported values: `none`, `gzip/gz`, `brotli/br`, `xz/LZMA`, `zstd/zst`. By default, compression will be autodetected by the file extension.                                                                                                                                                                                                                         |
| `extra_credentials`                          | Parameter is optional. Used to pass a `role_arn` for role-based access in ClickHouse Cloud. See [Secure S3](/products/cloud/guides/data-sources/accessing-s3-data-securely) for configuration steps.                                                                                                                                                                                        |

<h2 id="returned_value">
  Returned value
</h2>

A table with the specified structure for reading data in the specified Hudi table in S3.

<h2 id="virtual-columns">
  Virtual Columns
</h2>

* `_path` — Path to the file. Type: `LowCardinality(String)`.
* `_file` — Name of the file. Type: `LowCardinality(String)`.
* `_size` — Size of the file in bytes. Type: `Nullable(UInt64)`. If the file size is unknown, the value is `NULL`.
* `_time` — Last modified time of the file. Type: `Nullable(DateTime)`. If the time is unknown, the value is `NULL`.
* `_etag` — The etag of the file. Type: `LowCardinality(String)`. If the etag is unknown, the value is `NULL`.

<h2 id="related">
  Related
</h2>

* [Hudi engine](/reference/engines/table-engines/integrations/hudi)
* [Hudi cluster table function](/reference/functions/table-functions/hudiCluster)