Advanced techniques for performance tuning in DB2 include query optimization, which involves analyzing and fine-tuning SQL queries to improve execution efficiency. It often involves creating or modifying indexes, adjusting buffer pool sizes, and using advanced SQL features like common table expressions (CTEs) or window functions to optimize query execution plans. 

User-defined functions can enhance code readability and maintainability in DB2 by encapsulating complex logic, reducing the need for repetitive code, and promoting modular development. Encapsulating logic within functions improves code readability by abstracting implementation details and providing a clear interface for other developers to use. Additionally, modular development facilitates code reuse and simplifies maintenance efforts by isolating changes to specific functions rather than scattering them throughout the application. 

The FETCH statement in DB2 cursor operations retrieves rows from result sets. It is used to fetch the next row or a specified number of rows from the result set associated with a cursor. FETCH allows applications to retrieve and process data row by row, providing control over the data retrieval process. 

In a partitioned database environment, DB2 handles data distribution through hash-based distribution. This approach involves distributing data across partitions based on a hash function applied to one or more columns, known as partitioning keys. Hash-based distribution ensures even distribution of data across partitions, which helps in achieving balanced query processing and optimal performance in parallel processing environments. 

VARCHAR data type in DB2 is suitable for storing textual data of varying lengths, such as names, addresses, or descriptions. It allows for efficient storage and retrieval of character data. 

The DELETE FROM statement in SQL is used to delete all records from a table. It removes all rows from a table without deleting the table itself or its structure. This operation is irreversible, so it's important to use it with caution to avoid accidental data loss. 

DB2 Connect is a software product developed by IBM to allow applications to connect to DB2 databases. While it's versatile in its connectivity, one of its key focuses is integration with cloud systems like AWS and Azure. This integration enables seamless interaction between on-premises DB2 databases and cloud-based applications, fostering flexibility and scalability in the IT infrastructure. Cloud integration ensures that DB2 databases can adapt to modern cloud computing environments, supporting organizations in their journey towards digital transformation. 

The most effective approach to validate multiple fields in a Flutter form at once is by leveraging the Form widget's onFormSubmission callback with a centralized validation logic. This allows you to perform comprehensive validation across all fields when the form is submitted. By handling validation at the form level, you can coordinate the validation logic, provide a cohesive user experience, and efficiently manage the validation process for all fields in a centralized manner.

Implementing a user authentication flow in Flutter using an architectural pattern involves combining Provider and BLoC for a robust and scalable solution. Provider can be used for dependency injection, ensuring that authentication-related dependencies are easily accessible throughout the app. BLoC can manage the authentication state, handling complex logic and transitions between authentication states such as logged in, logged out, or authentication error. Combining Provider and BLoC provides a clean and maintainable architecture for user authentication in Flutter.

Flutter is expected to become a central framework for AI and IoT applications. Its versatility, hot-reloading feature, and expressive UI capabilities make it well-suited for integration with emerging technologies. Developers can leverage Flutter to create cross-platform applications that seamlessly incorporate AI and IoT functionalities, offering a unified development experience across different platforms. Understanding Flutter's potential in these domains is crucial for developers exploring advanced application development.