What does an Oracle instance govern?

An Oracle instance governs a set of shared databases and processes, which includes the memory structures and background processes required for the operation of one or more databases. When you start an Oracle database instance, it allocates memory for program execution and manages the input and output operations for the database. This allows multiple users and applications to access shared data concurrently, thereby facilitating efficient data management and operational performance.

The concept of an instance encapsulates the server-side resources that are employed to work with the database, which can include various processes that handle tasks such as managing concurrent connections, data input/output, locking mechanisms, and the execution of SQL commands. Thus, the correct understanding revolves around how instances relate to managing and maintaining shared resources among databases, enabling smooth and efficient data handling and user interaction.