Spotlight on Oracle 10.4 - Release Notes

The Memory panel shows detailed information on the Windows system.:

Total RAM — Shows the amount of actual RAM (Random Access Memory) in the machine.

Free (Physical Memory) — Displays the amount of physical memory available to applications.

Free Pct (Physical Memory) — Shows the percentage of physical memory that is currently available to applications.

Physical Memory Gauge —

Physical Memory shows the amount of physical memory (RAM) Windows is using.

Physical Memory usage will normally remain close to the total amount of physical memory installed on the system unless the amount of physical memory you have exceeds the amount of virtual memory that Windows is using.

Windows normally keeps some physical memory available (free) for immediate reuse.

Max Size — Shows the maximum amount of virtual memory available without expanding the paging file.

Free (Virtual Memory) — Shows the current amount of virtual memory available.

Free Pct (Virtual Memory) — Shows the percentage of virtual memory that is currently available to applications.

Virtual Memory gauge — Shows the total amount of Virtual Memory available without expanding the paging file, and the current amount of Virtual Memory that is in use.

Pages found in RAM —

Shows the percentage of soft pages versus hard pages found in RAM.

When a process requests a page that is not currently in its working set, the memory manager will look first in the physical memory of the system. This is called a soft page. If the memory page is not in physical memory, the page will have to be brought from disk. This is called a hard page.

This gauge shows the percentage of soft pages versus hard pages.

On a system that has a low level of activity, Pages found in RAM will be at or near 100%.

Read Hit Ratio —

Shows the percentage of disk requests that are found in cache memory.

Having requests answered from memory instead of disk cuts down on disk activity. A value of over 80% is likely to show an efficient use of system cache.

Pages Written/s —

Represents the rate at which virtual memory pages are written to disk from memory.

Virtual memory pages are written to disk when there is not enough physical memory (RAM) available for an application. This forces a dormant application to "swap" some of its used memory to the paging file (disk).

Pages Read/s —

Represents the rate at which virtual memory pages are swapped from disk into memory.

This occurs when a program that previously had part of its data or application memory "swapped" to disk requires the memory page(s) in RAM again to work on.

Disk Writes/s — Represents the rate of data being written to disk from memory. There is one Disk Writes dataflow for every disk in the Disks panel.

Disk Reads/s — Represents the rate of data being read from disk to memory. There is one Disk Reads dataflow for every disk in the Disks panel.