What does the term "PGA" stand for in database metrics?

The term "PGA" stands for Process Global Area in the context of database metrics. This refers to a memory region that contains data and control information for a server process in an Oracle database. The PGA is crucial for the performance and functioning of the database as it holds information such as the stack space, session variables, and cursor information for executing SQL statements.

Understanding the PGA is important for database performance tuning and management, since optimizing memory allocation can lead to better execution speed and resource utilization. This area is not shared between different processes, which differentiates it from Global Areas associated with shared memory structures in a database system.

The other options presented do not accurately describe the nature of the PGA. For instance, "Primary Global Allocation" and "Process Group Allocation" do not align with recognized terminology in database management, while "Public Global Area" is not a standard term related to the memory architecture of Oracle databases. This clarity helps in reinforcing the significance of the PGA in understanding database performance metrics.