In DB2, a cursor is primarily used to process result sets. Cursors allow fetching and processing individual rows from a result set returned by a SQL query. They enable iterative processing of query results, facilitating row-by-row operations within application programs. 

DB2 is a robust relational database management system (RDBMS) known for its support across various platforms, including mainframes, distributed systems, and cloud. It offers advanced features like high availability, disaster recovery, and security mechanisms to protect data integrity and confidentiality. 

Different versions of DB2 introduce new features and enhancements that may affect the compatibility of existing applications. For instance, upgrading to a newer version may offer improved performance optimizations, but it could also require modifications to existing code to leverage new features effectively. Therefore, understanding the impact of version upgrades on application compatibility is essential for ensuring a smooth transition and optimal performance. 

The First Normal Form (1NF) ensures that there are no repeating groups in a table by ensuring that each column contains atomic values, and each column has a unique name. This is the fundamental level of normalization in DB2. 

Locking in DB2 serves the purpose of preventing concurrent transactions from accessing the same data concurrently, ensuring data integrity and consistency. This helps in avoiding situations such as dirty reads and conflicting updates, thereby maintaining the accuracy and reliability of the data. It ensures that only one transaction can modify data at a time, preventing inconsistencies. 

Indexing contributes to query optimization in DB2 by organizing data in a structured way, allowing the database engine to efficiently locate and retrieve data, thereby improving query performance. It helps in reducing the number of rows scanned during query execution, resulting in faster response times. 

User-defined functions in DB2 can encapsulate procedural logic for reuse in queries. This means that developers can implement custom logic within functions to perform specific operations, such as calculations, data transformations, or validations, and then reuse these functions in various SQL queries, enhancing code readability and maintainability. 

Materialized Views are a common technique used in denormalization. They are precomputed views stored on disk, which can greatly improve query performance by reducing the need for joins and calculations. 

Too many indexes on a table in DB2 can lead to increased maintenance overhead. This is because each index needs to be updated whenever there are changes to the table data, which can impact performance. 

Command Line Tools offer a more efficient and flexible approach for real-time data inspection and adjustments. With Command Line Tools, DBAs can directly query and analyze performance metrics using SQL commands such as EXPLAIN and MON_GET_TABLE. This method provides more granular control and visibility into database performance, making it the preferred choice for quick assessments and adjustments. 

The UNLOAD utility in DB2 is specifically designed for extracting data from DB2 tables and writing it to an external file. It allows users to export data in various formats, such as delimited text files or binary files, making it suitable for data exchange and backup purposes. The UNLOAD utility offers flexibility and efficiency in extracting large volumes of data from DB2 tables. 

In a RIGHT JOIN operation, all rows from the right table are retained in the result set, even if there are no matching rows in the left table. This ensures that data from the right table is included in the output, regardless of matching criteria.