Point-in-time recovery in DB2 typically involves restoring the database to a consistent state prior to the corruption incident. This requires performing a full database backup, restoring it to a different location, and applying transaction logs up to the desired point in time to achieve consistency. 

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. 

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. 

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. 

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. 

Database Services in DB2 architecture primarily handle data storage management tasks such as organizing data on disk, managing buffer pools, and allocating storage space efficiently to optimize performance and resource utilization. 

When designing user-defined functions in DB2, it's crucial to consider optimizing for reusability. This involves writing functions that can be utilized across multiple queries and applications, reducing the need for redundant code. By focusing on reusability, developers can enhance code maintenance and improve overall application performance. 

Option 2: Properties. Attributes within tags in DB2 define additional properties of the database object. These properties provide detailed information about the object, aiding in its understanding and usage within the database environment. 

A materialized view in DB2 is a database object that contains the results of a query and is physically stored on disk, allowing for faster query performance. Unlike regular views, which are virtual and only stored as a predefined query, materialized views are materialized or precomputed and updated automatically when the underlying data changes, ensuring data consistency. 

Log shipping in disaster recovery ensures that changes made to the primary DB2 database are replicated to a standby database in real-time or near real-time. This replication allows for point-in-time recovery by applying transaction logs to the standby database, ensuring minimal data loss in the event of a disaster.