I/O optimization aims to enhance read and write operations by improving disk access patterns, reducing seek times, and optimizing data retrieval mechanisms. 

Prioritizing alerts based on severity allows the administrator to focus on critical issues first, ensuring timely resolution. This prevents wasting time on false alarms and enables efficient handling of urgent matters to maintain database availability and performance. 

Configuring Communication Protocols involves ensuring proper configuration of network protocols and settings to prevent communication errors. This includes verifying network connectivity, firewall settings, and protocol configurations between the application and the database server. 

When choosing a clustering key in DB2, it's essential to consider various factors such as the cardinality of the key (i.e., the uniqueness of values), access patterns of queries (i.e., how frequently certain data is accessed), and the distribution of data across partitions. These factors influence query performance, as they affect the efficiency of data retrieval and storage. 

DB2 enforces access control on database objects primarily through user authentication, where only authorized users with appropriate privileges can access and manipulate the data stored within the database. 

DB2 optimizes the execution plan when querying a view to retrieve data more efficiently. By analyzing the underlying tables and the view definition, DB2 can optimize join paths, access methods, and other factors to enhance query performance. 

The primary objective of normalization in DB2 is to minimize redundancy by organizing data efficiently. Reducing redundancy helps improve data integrity, save storage space, and ensure consistency in the database. 

User-defined functions can contribute to improving performance in DB2 applications by optimizing for reusability. When functions are designed to be reused across multiple queries and applications, it reduces the need for redundant code, leading to improved code maintenance and enhanced application performance. Additionally, by encapsulating frequently used logic within functions, developers can streamline query execution and promote code modularity. 

A scrollable cursor in DB2 allows for navigating both forward and backward through the result set obtained from a query. This feature provides flexibility to applications in iterating over query results in different directions based on their requirements. 

OLE DB (Object Linking and Embedding Database) plays a crucial role in integrating DB2 with Microsoft applications. It provides a set of COM (Component Object Model) interfaces that enable applications to access and manipulate data from various data sources, including DB2. OLE DB offers a unified way for Microsoft applications such as Excel, Access, and SQL Server to communicate with DB2 databases, allowing seamless data exchange and integration. By using OLE DB, developers can build robust and scalable solutions that leverage the capabilities of both DB2 and Microsoft applications.