improve workload group

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

@@ -5,7 +5,7 @@ import FunctionDescription from '@site/src/components/FunctionDescription';
 
 <FunctionDescription description="Introduced or updated: v1.2.743"/>
 
-Creates a workload group with specified quota settings.
+Creates a workload group with specified quota settings. Workload groups control resource allocation and query concurrency by binding to users. When a user submits queries, the workload group limits are applied based on the user's assigned group.
 
 ## Syntax
 
@@ -26,7 +26,64 @@ CREATE WORKLOAD GROUP [IF NOT EXISTS] <group_name>
 
 ## Examples
 
+### Basic Example
+
 ```sql
-CREATE WORKLOAD GROUP analytics WITH cpu_quota = '20%', query_timeout = '10m';
+-- Create workload groups
+CREATE WORKLOAD GROUP IF NOT EXISTS interactive_queries 
+WITH cpu_quota = '30%', memory_quota = '20%', max_concurrency = 2;
+
+CREATE WORKLOAD GROUP IF NOT EXISTS batch_processing 
+WITH cpu_quota = '70%', memory_quota = '80%', max_concurrency = 10;
 ```
 
+### User Assignment
+
+Users must be assigned to workload groups to enable resource limiting. When users execute queries, the system applies the workload group's restrictions automatically.
+
+```sql
+-- Create and assign user
+CREATE USER analytics_user IDENTIFIED BY 'password123';
+ALTER USER analytics_user WITH SET WORKLOAD GROUP = 'interactive_queries';
+
+-- Reassign to different workload group
+ALTER USER analytics_user WITH SET WORKLOAD GROUP = 'batch_processing';
+
+-- Remove from workload group (user will use default unlimited resources)
+ALTER USER analytics_user WITH UNSET WORKLOAD GROUP;
+
+-- Check user's workload group
+DESC USER analytics_user;
+```
+
+## Resource Quota Normalization
+
+### Quota Limits
+- Each workload group's `cpu_quota` and `memory_quota` can be set up to `100%` (1.0)
+- The total sum of all quotas across workload groups can exceed 100%
+- Actual resource allocation is **normalized** based on relative proportions
+
+### How Quota Normalization Works
+
+Resources are allocated proportionally based on each group's quota relative to the total:
+
+```
+Actual Allocation = (Group Quota) / (Sum of All Group Quotas) × 100%
+```
+
+**Example 1: Total quotas = 100%**
+- Group A: 30% quota → Gets 30% of resources (30/100)
+- Group B: 70% quota → Gets 70% of resources (70/100)
+
+**Example 2: Total quotas > 100%**
+- Group A: 60% quota → Gets 40% of resources (60/150)
+- Group B: 90% quota → Gets 60% of resources (90/150)
+- Total quotas: 150%
+
+**Example 3: Total quotas < 100%**
+- Group A: 20% quota → Gets 67% of resources (20/30)
+- Group B: 10% quota → Gets 33% of resources (10/30)
+- Total quotas: 30%
+
+**Special Case:** When only one workload group exists, it gets 100% of warehouse resources regardless of its configured quota.
+

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

@@ -18,5 +18,5 @@ DROP WORKLOAD GROUP [IF EXISTS] <workload_group_name>
 This example removes the `test_workload_group` workload group:
 
 ```sql
-DROP WORKLOAD GROUP test_warehouse;
+DROP WORKLOAD GROUP test_workload_group;
 ```

docs/en/sql-reference/10-sql-commands/00-ddl/20-workload-group/index.md

@@ -2,23 +2,40 @@
 title: Workload Group
 ---
 
-This page provides a comprehensive overview of Workload Group operations in Databend, organized by functionality for easy reference.
+Workload groups enable resource management and query concurrency control in Databend by allocating CPU, memory quotas and limiting concurrent queries for different user groups.
 
-## Workload Group Management
+## How It Works
 
+1. **Create workload groups** with specific resource quotas (CPU, memory, concurrency limits)
+2. **Assign users** to workload groups using `ALTER USER`
+3. **Query execution** automatically applies the workload group's resource limits based on the user
+
+## Quick Example
+
+```sql
+-- Create workload group
+CREATE WORKLOAD GROUP analytics WITH cpu_quota = '50%', memory_quota = '30%', max_concurrency = 5;
+
+-- Assign user to workload group
+CREATE USER analyst IDENTIFIED BY 'password';
+ALTER USER analyst WITH SET WORKLOAD GROUP = 'analytics';
+```
+
+## Command Reference
+
+### Management
 | Command | Description |
 |---------|-------------|
-| [CREATE WORKLOAD GROUP](create-workload-group.md) | Creates a new workload group for resource management |
-| [ALTER WORKLOAD GROUP](alter-workload-group.md) | Modifies an existing workload group configuration |
+| [CREATE WORKLOAD GROUP](create-workload-group.md) | Creates a new workload group with resource quotas |
+| [ALTER WORKLOAD GROUP](alter-workload-group.md) | Modifies workload group configuration |
 | [DROP WORKLOAD GROUP](drop-workload-group.md) | Removes a workload group |
-| [RENAME WORKLOAD GROUP](rename-workload-group.md) | Changes the name of a workload group |
-
-## Workload Group Information
+| [RENAME WORKLOAD GROUP](rename-workload-group.md) | Renames a workload group |
 
+### Information
 | Command | Description |
 |---------|-------------|
-| [SHOW WORKLOAD GROUPS](show-workload-groups.md) | Lists all workload groups and their configurations |
+| [SHOW WORKLOAD GROUPS](show-workload-groups.md) | Lists all workload groups and their settings |
 
-:::note
-Workload groups in Databend allow you to manage and prioritize resource allocation for different types of queries and users, helping optimize performance and resource utilization.
+:::tip
+Resource quotas are normalized across all workload groups in a warehouse. For example, if two groups have 60% and 40% CPU quotas, they get 60% and 40% of actual resources respectively.
 :::

docs/en/sql-reference/10-sql-commands/00-ddl/20-workload-group/rename-workload-group.md

@@ -18,6 +18,6 @@ RENAME WORKLOAD GROUP <current_name> TO <new_name>
 This example renames `test_workload_group_1` to `test_workload_group`:
 
 ```sql
-RENAME WAREHOUSE test_workload_group_1 TO test_workload_group;
+RENAME WORKLOAD GROUP test_workload_group_1 TO test_workload_group;
 ```