In this section, we will learn about the database components involved in the execution of an external procedure.
The extproc agent plays the most vital role in interfacing external procedures in the Oracle Database. It is a process started by the Oracle Database or database listener, which facilitates the execution of an external procedure whenever required. It carries relevant information such as the library path, procedure name, and arguments. It returns the result of the execution back to the database processing engine.
In a dedicated server mode, each session will have a new instance of the extproc process. In a multiuser application, multiple sessions with multiple extproc processes may result in a disproportionate allocation of memory resources. In a shared server mode, a multithreaded extproc agent can provide the efficient utilization of server resources by maintaining a shared pool of the extproc processes.