Visual Explain provides comprehensive insights into query execution, aiding DB2 DBAs and developers in understanding how queries are executed, optimizing their performance, and identifying potential areas for improvement. 

The Health Monitor typically tracks metrics related to performance, usage, availability, and resource utilization. Performance metrics help in assessing the efficiency of database operations, usage metrics provide insights into the frequency of database access, availability metrics gauge the accessibility of the database system, and resource utilization metrics monitor the consumption of system resources such as CPU and memory. 

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. 

A cursor with a FOR UPDATE clause allows for updating data. This clause is used to lock the rows returned by the cursor for update operations, enabling modifications to the data directly through the cursor. It is commonly used in scenarios where data modifications need to be made based on specific criteria. 

In DB2, a view represents a virtual table that does not store data physically but rather provides a logical representation of data stored in one or more underlying tables. Queries against views are processed by fetching data from the underlying tables based on the view's definition.