## Overview

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> [!NOTE]
> - Use the Chrome browser to access this interactive lab guide.
> - The lab environment takes about **3 minutes** to initialize after you start it, and completing the demo typically takes less than **5 minutes**. Please terminate your lab instance as soon as you finish the demo.
> - This lab uses a Python-based workload for convenience, the Online Schema Change feature is language-agnostic and works with all programming languages.

In this short demo, you will perform an online schema without stopping the application. For a deeper understanding of Online DDL, explore the labs [Introduction to TiDB Cloud](/labs/demo_203) and [Working with TiDB Cloud Using mysql-connector-python](/labs/demo_405).

### Tasks

- Start a read write database workload and keep it running.
- Add a new column to the testing table while the workload is running.

> [!TIP]
> Click **Start** to launch the lab environment.
> Once the environment is ready, the resources assigned to your hands-on session will be populated with the actual values, so you can follow the lab guide step-by-step to complete the short demo.