Configuring the Operating System
This one is usually easy, since (in most cases) it’s not your job! In most installations, there is a system administrator or manager who is responsible for addressing operating system and hardware issues. This system administrator is usually an expert on the hardware and operating system software, and most DBAs are not in a position to second-guess him or her. While deferring to the system administrator’s expertise, here are a few points you might want to make sure are addressed:
Physical memory should be fully utilized, but swapping (in environments that swap memory) should not occur. Swapping memory to disk is a very slow process, so if your system needs more memory, buy more memory! In particular, make certain that you do not create a System Global Area (SGA) that is too big for physical memory, since swapping of the SGA will severely degrade Oracle performance.
The CPU should approach 100% utilization at peaks, but processes should not have to wait for the CPU.
Disks and controllers should be running at or near their optimal capacities (usually 60 to 90% of maximum) with minimal I/O waits. As the DBA, you do have some control over this area as well, as we’ll describe later in this chapter.
Network throughput should not be a bottleneck. Consider backbone networks to link servers to each other, and separate client/server traffic from server/server traffic where possible.
Try to keep your Oracle server machine a pure server, and move users to another machine.
Be sure any operating system components (including patches) that may affect Oracle are installed.
Because Oracle is a major vendor in the database marketplace, most major hardware vendors have Oracle “experts” on staff who can provide advice on hardware and operating system issues that may affect Oracle’s execution on their hardware. Take advantage of this expertise!