Data Lake Formation:Access DLF from MaxCompute

Step 1: Grant permissions

The following table shows which account type performs each task in this step.

Step 2: Create a Paimon_DLF external data source

1. Log on to the MaxCompute console and select your region.

2. In the left navigation pane, choose Manage Configurations > External Data Source.

3. Click Create External Data Source.

4. Configure the following parameters:

   Parameter	Required	Description
   External Data Source Type	Required	Select Paimon_DLF
   External Data Source Name	Required	Starts with a letter; lowercase letters, underscores, and digits only; maximum 128 characters. Example: paimon_dlf
   Description	Optional	Custom description
   Region	Required	Defaults to the current region
   Authentication And Authorization	Required	Defaults to Alibaba Cloud RAM role
   Service-linked Role	Required	Auto-generated
   Endpoint	Required	Auto-generated. For the China (Hangzhou) region: cn-hangzhou-intranet.dlf.aliyuncs.com
   Foreign Server Supplemental Properties	Optional	Additional attributes for the external data source

5. Click OK.

6. On the External Data Source page, find the new data source and click Details in the Actions column to verify the configuration.

Step 3: Create an external project

1. Log on to the MaxCompute console and select your region.

2. In the left navigation pane, choose Manage Configurations > Projects.

3. On the External Project tab, click Create Project.

4. Configure the following parameters and click OK:

   Parameter	Required	Description
   Project Type	Required	Defaults to External Project
   Region	Required	Defaults to the current region; cannot be changed
   Project Name (Globally Unique)	Required	Starts with a letter; letters, digits, and underscores only; 3–28 characters
   MaxCompute Foreign Server Type	Optional	Defaults to Paimon_DLF
   MaxCompute Foreign Server	Optional	Use Existing to select a previously created external data source, or Create Foreign Server to create a new one
   MaxCompute Foreign Server Name	Required	Select from existing data sources, or enter the name of the new one
   Data Catalog	Required	The DLF data catalog to attach
   Billing Method	Required	Subscription or Pay-as-you-go
   Default Quota	Required	Select an existing quota
   Description	Optional	Custom description

Step 4: Query and write data using SQL

Select a connection tool to log on to the external project, then use the following SQL commands.

-- Enable schema syntax at the session level.
SET odps.namespace.schema=true;
SHOW schemas;

-- Sample output:
-- ID = 20250919****am4qb
-- default
-- system
-- OK

-- Replace <schema_name> with the schema name shown in the output above.
USE schema <schema_name>;
SHOW tables;

-- Sample output:
-- ID = 20250919****am4qb
-- acs:ram::<uid>:root  emp
-- OK

-- Replace <schema_name> with your schema name.
CREATE schema <schema_name>;

-- Create a table.
CREATE TABLE [IF NOT EXISTS] <table_name>
(
  <col_name> <data_type>,
  ...
)
[COMMENT <table_comment>]
[PARTITIONED BY (<col_name> <data_type>, ...)]
;

-- Insert data.
INSERT {INTO|OVERWRITE} TABLE <table_name> [PARTITION (<pt_spec>)] [(<col_name> [,<col_name> ...])]
<select_statement>
FROM <from_statement>

CREATE TABLE schema_table(id int, name string);

INSERT INTO schema_table VALUES (101, 'Zhang San'), (102, 'Li Si');

-- Verify the data.
SELECT * FROM schema_table;

-- Result:
-- +------------+------------+
-- | id         | name       |
-- +------------+------------+
-- | 101        | Zhang San  |
-- | 102        | Li Si      |
-- +------------+------------+

USE schema default;
SHOW tables;

-- Sample output:
-- ID = 20250919*******yg5
-- acs:ram::<uid>:root  emp
-- acs:ram::<uid>:root  emp_detail
-- acs:ram::<uid>:root  test_table
-- OK

-- Read data.
SELECT * FROM test_table;

-- Result:
-- +------------+------------+
-- | id         | name       |
-- +------------+------------+
-- | 101        | Zhang San  |
-- | 102        | Li Si      |
-- +------------+------------+

-- Write data and verify.
INSERT INTO test_table VALUES (103, 'Wang Wu');

SELECT * FROM test_table;

-- Result:
-- +------------+------------+
-- | id         | name       |
-- +------------+------------+
-- | 101        | Zhang San  |
-- | 102        | Li Si      |
-- | 103        | Wang Wu    |
-- +------------+------------+

"You are not authorized to perform this action" when creating an external project

The RAM user lacks the required permissions. Check the following:

1. Make sure AliyunMaxComputeFullAccess is attached to the RAM user. See Step 1.

2. Make sure DLF permissions are granted. Creating a Paimon_DLF external project requires selecting a DLF catalog, which requires DLF access. See Step 1.

"Forbidden: User acs:ram::\<uid\>:user/\*\* doesn't have privilege LIST on DATABASE default" when running SHOW TABLES

The RAM user lacks data plane permissions on the DLF catalog.

1. Log on to the DLF console. In the left navigation pane, click System And Security. On the Access Control tab, refresh the page and check whether the RAM user appears.

2. If the user exists, click Roles and grant the required permissions to the RAM user.