* Stack: This is a relatively small (kilobytes usually) portion of an Oracle process's memory. The stack is used to push and pop process variables, and also to hold command-line arguments while they are being processed-that is, popped off the stack.5

Never mention the approach I outline here to your operating system vendor. And it's probably not a good idea to mention this to operating system administrators either, unless they are also Oracle administrators. Also be aware that every operating system uses different words, terms, and algorithms. But this general three-step process provides the guidance you need when understanding if there is a memory bottleneck-excuse me, I mean memory pressure.

In memory, paging is the first line of defense. A process asks the operating system for memory (for example, issuing the C malloc call), and the operating system looks for free memory. First, the operating system looks for free memory pages or memory from other processes that have not recently been used. This is called a page fault, but not a physical page fault. (The fault part is unfortunate, but that's what it's called.)