docs: add WORKER documentation for PR #19383

docs/en/sql-reference/10-sql-commands/00-ddl/10-udf/ddl-create-function.md

@@ -187,3 +187,53 @@ export function calculateAge(birthDateStr) {
 }
 $$;
 ```
+
+## Worker Management for UDFs
+
+In Databend Cloud, each UDF has an associated **Worker** that manages its execution environment in the sandbox. After creating a UDF, you may need to manage its worker for optimal performance and resource utilization.
+
+### Creating a Worker for Your UDF
+
+```sql
+-- Create a worker for your UDF (worker name should match UDF name)
+CREATE WORKER calculate_age_js WITH
+    size='small',
+    auto_suspend='300',
+    auto_resume='true';
+```
+
+### Managing Worker Resources
+
+```sql
+-- View all workers
+SHOW WORKERS;
+
+-- Adjust worker settings
+ALTER WORKER calculate_age_js SET size='medium', auto_suspend='600';
+
+-- Add tags for organization
+ALTER WORKER calculate_age_js SET TAG 
+    environment='production',
+    team='analytics',
+    purpose='age-calculation';
+```
+
+### Worker Lifecycle
+
+```sql
+-- Suspend worker when not in use
+ALTER WORKER calculate_age_js SUSPEND;
+
+-- Resume worker when needed
+ALTER WORKER calculate_age_js RESUME;
+
+-- Remove worker when UDF is no longer needed
+DROP WORKER calculate_age_js;
+```
+
+### Environment Variables
+
+For security reasons, environment variables for UDFs are managed separately in the cloud console. After creating a UDF and its worker, configure any required environment variables through the Databend Cloud interface.
+
+For more information, see [Worker Management](../20-worker/index.md).
+```

docs/en/sql-reference/10-sql-commands/00-ddl/20-worker/_category_.json

@@ -0,0 +1,8 @@
+{
+  "label": "Worker",
+  "position": 20,
+  "link": {
+    "type": "generated-index",
+    "description": "Worker management commands for UDF execution environments in Databend Cloud sandbox."
+  }
+}

docs/en/sql-reference/10-sql-commands/00-ddl/20-worker/alter-worker.md

@@ -0,0 +1,103 @@
+---
+title: ALTER WORKER
+sidebar_position: 3
+---
+
+import FunctionDescription from '@site/src/components/FunctionDescription';
+
+<FunctionDescription description="Introduced: v1.3.0"/>
+
+Modifies the settings, tags, or state of an existing worker.
+
+## Syntax
+
+```sql
+-- Modify worker options
+ALTER WORKER <worker_name> SET <option_name> = '<value>' [, <option_name> = '<value>' ...]
+ALTER WORKER <worker_name> UNSET <option_name> [, <option_name> ...]
+
+-- Modify worker tags
+ALTER WORKER <worker_name> SET TAG <tag_name> = '<tag_value>' [, <tag_name> = '<tag_value>' ...]
+ALTER WORKER <worker_name> UNSET TAG <tag_name> [, <tag_name> ...]
+
+-- Change worker state
+ALTER WORKER <worker_name> SUSPEND
+ALTER WORKER <worker_name> RESUME
+```
+
+| Parameter    | Description                                                                 |
+| ------------ | --------------------------------------------------------------------------- |
+| worker_name  | The name of the worker to modify                                            |
+| option_name  | One of: `size`, `auto_suspend`, `auto_resume`, `max_cluster_count`, `min_cluster_count` |
+| value        | The new value for the option (as a string)                                  |
+| tag_name     | The name of the tag to set or unset                                         |
+| tag_value    | The value for the tag                                                       |
+
+## Options
+
+The same options available in `CREATE WORKER` can be modified using `ALTER WORKER`:
+
+| Option                | Description                                                                 |
+| --------------------- | --------------------------------------------------------------------------- |
+| `size`                | Compute size of the worker (e.g., 'small', 'medium')                        |
+| `auto_suspend`        | Idle timeout before automatic suspend (seconds)                             |
+| `auto_resume`         | Whether auto-resume is enabled ('true' or 'false')                          |
+| `max_cluster_count`   | Upper bound for auto-scaling clusters                                       |
+| `min_cluster_count`   | Lower bound for auto-scaling clusters                                       |
+
+## Examples
+
+### Modify Worker Options
+
+Change the size and auto-suspend settings of a worker:
+
+```sql
+ALTER WORKER read_env SET size='medium', auto_suspend='600';
+```
+
+Reset specific options to their default values:
+
+```sql
+ALTER WORKER read_env UNSET size, auto_suspend;
+```
+
+### Manage Worker Tags
+
+Add or update tags on a worker:
+
+```sql
+ALTER WORKER read_env SET TAG purpose='sandbox', owner='ci';
+```
+
+Remove tags from a worker:
+
+```sql
+ALTER WORKER read_env UNSET TAG purpose, owner;
+```
+
+### Control Worker State
+
+Suspend a worker (stop its execution environment):
+
+```sql
+ALTER WORKER read_env SUSPEND;
+```
+
+Resume a suspended worker:
+
+```sql
+ALTER WORKER read_env RESUME;
+```
+
+## Notes
+
+1. **Atomic Operations**: Multiple options can be modified in a single `ALTER WORKER` statement.
+2. **State Changes**: `SUSPEND` and `RESUME` are mutually exclusive with option modifications.
+3. **Tag Management**: Tags are useful for categorizing and organizing workers. They can be used for cost allocation, environment identification, or team ownership.
+4. **Validation**: Option values are validated according to the same rules as `CREATE WORKER`.
+
+## Related Topics
+
+- [CREATE WORKER](create-worker.md) - Create a new worker
+- [SHOW WORKERS](show-workers.md) - List workers and their current settings
+- [DROP WORKER](drop-worker.md) - Remove a worker

docs/en/sql-reference/10-sql-commands/00-ddl/20-worker/create-worker.md

@@ -0,0 +1,75 @@
+---
+title: CREATE WORKER
+sidebar_position: 1
+---
+
+import FunctionDescription from '@site/src/components/FunctionDescription';
+
+<FunctionDescription description="Introduced: v1.3.0"/>
+
+Creates a new worker for UDF execution in the sandbox environment.
+
+## Syntax
+
+```sql
+CREATE WORKER [ IF NOT EXISTS ] <worker_name>
+    [ WITH size = '<size_value>']
+    [ WITH auto_suspend = '<suspend_seconds>']
+    [ WITH auto_resume = '<true|false>']
+    [ WITH max_cluster_count = '<count>']
+    [ WITH min_cluster_count = '<count>']
+```
+
+| Parameter       | Description                                                                                   |
+| --------------- | --------------------------------------------------------------------------------------------- |
+| `IF NOT EXISTS` | Optional. If specified, the command succeeds without changes if the worker already exists.    |
+| worker_name     | The name of the worker to create. Corresponds to a UDF name.                                  |
+
+## Options
+
+| Option                | Type / Values                          | Default       | Description                                                                 |
+| --------------------- | -------------------------------------- | ------------- | --------------------------------------------------------------------------- |
+| `size`                | String (e.g., 'small', 'medium')       | Platform default | Controls the compute size of the worker                                    |
+| `auto_suspend`        | String (seconds)                       | Platform default | Idle timeout before automatic suspend                                      |
+| `auto_resume`         | String ('true' or 'false')             | Platform default | Controls whether incoming requests wake the worker automatically           |
+| `max_cluster_count`   | String (count)                         | Platform default | Upper bound for auto-scaling clusters                                      |
+| `min_cluster_count`   | String (count)                         | Platform default | Lower bound for auto-scaling clusters                                      |
+
+- Options are specified as key-value pairs using the `WITH` keyword
+- All option values are passed as strings and must be enclosed in single quotes
+- Options may appear in any order
+- Option names are case-insensitive but shown here in lowercase for consistency
+
+## Examples
+
+Create a basic worker for a UDF named `read_env`:
+
+```sql
+CREATE WORKER read_env;
+```
+
+Create a worker with `IF NOT EXISTS` to avoid errors if it already exists:
+
+```sql
+CREATE WORKER IF NOT EXISTS read_env;
+```
+
+Create a worker with custom configuration:
+
+```sql
+CREATE WORKER read_env WITH size='small', auto_suspend='300', auto_resume='true', max_cluster_count='3', min_cluster_count='1';
+```
+
+## Notes
+
+1. **UDF Association**: Each worker corresponds to a single UDF. The worker name should match the UDF name.
+2. **Environment Variables**: Environment variables for UDFs are managed separately in the cloud console for security reasons.
+3. **Resource Management**: Workers manage the execution environment and resources for their associated UDFs.
+4. **Cloud Integration**: Workers are integrated with Databend Cloud's control plane for lifecycle management.
+
+## Related Topics
+
+- [ALTER WORKER](alter-worker.md) - Modify worker settings
+- [SHOW WORKERS](show-workers.md) - List available workers
+- [DROP WORKER](drop-worker.md) - Remove a worker
+- [User-Defined Functions](../10-udf/index.md) - Learn about UDFs in Databend

docs/en/sql-reference/10-sql-commands/00-ddl/20-worker/drop-worker.md

@@ -0,0 +1,61 @@
+---
+title: DROP WORKER
+sidebar_position: 4
+---
+
+import FunctionDescription from '@site/src/components/FunctionDescription';
+
+<FunctionDescription description="Introduced: v1.3.0"/>
+
+Removes a worker from the system.
+
+## Syntax
+
+```sql
+DROP WORKER [ IF EXISTS ] <worker_name>
+```
+
+| Parameter       | Description                                                                                   |
+| --------------- | --------------------------------------------------------------------------------------------- |
+| `IF EXISTS`     | Optional. If specified, the command succeeds without errors if the worker does not exist.     |
+| worker_name     | The name of the worker to remove.                                                             |
+
+## Examples
+
+Remove a worker:
+
+```sql
+DROP WORKER read_env;
+```
+
+Remove a worker only if it exists (avoids errors if the worker doesn't exist):
+
+```sql
+DROP WORKER IF EXISTS read_env;
+```
+
+## Behavior
+
+1. **Resource Cleanup**: When a worker is dropped, all associated resources are released.
+2. **UDF Association**: Dropping a worker does not automatically drop the associated UDF. The UDF can still exist but will not have an execution environment.
+3. **Irreversible Operation**: Dropping a worker cannot be undone. The worker must be recreated if needed.
+4. **Dependencies**: Ensure no active executions are using the worker before dropping it.
+
+## Error Conditions
+
+- `UnknownWorker`: If the worker does not exist and `IF EXISTS` is not specified.
+- `WorkerInUse`: If the worker is currently executing UDFs or has pending operations.
+
+## Notes
+
+1. **Safety First**: Use `IF EXISTS` to make your scripts idempotent and avoid unnecessary errors.
+2. **Check State**: Consider checking the worker's state with `SHOW WORKERS` before dropping it.
+3. **Cleanup Order**: If you're cleaning up a UDF and its worker, drop the worker first, then the UDF if desired.
+4. **Cloud Integration**: Worker deletion is coordinated with Databend Cloud's control plane to ensure proper resource cleanup.
+
+## Related Topics
+
+- [CREATE WORKER](create-worker.md) - Create a new worker
+- [SHOW WORKERS](show-workers.md) - List available workers
+- [ALTER WORKER](alter-worker.md) - Modify worker settings
+- [User-Defined Functions](../10-udf/index.md) - Learn about UDFs in Databend