The done property in the object returned by the next() method of a generator indicates whether the generator has completed its execution. When done is true, it means the generator has finished, and no more values will be generated. This is crucial for controlling the flow of iteration and termination of the generator.

Template literals in JavaScript can be used for multi-line string formatting by directly including line breaks within the backticks. This makes it easier to create and maintain multiline strings without the need for explicit concatenation or escape characters.

Indexes in DB2 improve query performance. They serve as a data structure that helps in quickly locating and accessing specific rows within a table based on the indexed columns. By creating indexes on columns frequently used in search criteria or join conditions, DB2 can efficiently retrieve data, leading to faster query execution times and overall improved system performance. 

DB2 manages encryption keys for encrypted data by using a key management system to securely store and distribute encryption keys. This ensures that only authorized users can access encrypted data securely. 

The LOAD utility in DB2 is used to insert large volumes of data efficiently into database tables. It is particularly useful when dealing with massive data loads, such as during initial database population or data warehousing operations. The LOAD utility bypasses much of the normal processing done during INSERT operations, resulting in faster data loading. 

DB2 implements optimistic concurrency control through MVCC (Multi-Version Concurrency Control). This mechanism allows transactions to proceed without waiting for others to complete, by maintaining multiple versions of a data item. When a transaction reads a data item, it gets a timestamp, and if another transaction updates the same data after that timestamp, the database creates a new version of the data, maintaining the older version for read consistency. MVCC reduces contention and improves concurrency in DB2 systems. 

Third-party command line tools may offer specialized features for performance tuning tasks in DB2 administration. These tools often provide advanced performance analysis, optimization, and tuning capabilities to enhance the overall performance and efficiency of DB2 databases and applications. 

Performance tuning in DB2 can improve various operations such as data retrieval by optimizing SQL queries, creating appropriate indexes, and configuring memory settings to enhance overall system performance. 

Encryption in DB2 ensures the confidentiality of data, meaning that even if unauthorized users gain access to the data, they won't be able to understand or decipher it without the proper decryption keys. This ensures that sensitive information remains protected from unauthorized access or viewing. 

The AVG() function in DB2 is specifically designed to calculate the average value of a numeric column. It adds up all the values in the column and divides them by the total number of rows. 

Dynamic SQL statement caching in DB2 refers to the process of storing frequently executed SQL statements in a cache memory. This feature improves performance as the database engine doesn't need to recompile these statements every time they are executed. Furthermore, it indirectly enhances security by reducing the exposure of SQL statements to potential attackers. Since the cached statements are already compiled and optimized, there is less risk of attackers exploiting vulnerabilities in the compilation process to execute malicious code or gain unauthorized access to the database. 

DB2 handles SQL injection attacks by sanitizing user inputs before executing SQL queries. SQL injection is a common technique used by attackers to manipulate database queries by inserting malicious SQL code into input fields. By sanitizing inputs, DB2 ensures that any potentially harmful characters or commands are escaped or removed, thus preventing the injection of unauthorized SQL code. This approach helps to mitigate the risk of SQL injection attacks and safeguard the integrity and security of the database.