One of the most critical things for an Oracle DBA to remember is that the
Oracle database is subject to resource limitations. Because an Oracle database runs within a hardware environment, external factors can greatly impact Oracle performance. The external environment for a database includes:
- The operating system software
- The network
- The physical disks
- The memory and CPU on the host
These external components are often referred to as the operating system environment, or OS for short.
An Oracle database does not operate in a vacuum. The database instance consists of a region in the memory of the computer, a section of disk
devices, and a set of processes that run on the database server.
Note that the Oracle database background processes are ordinary processes to the OS environment. They have to wait for CPU services just like all other processes on the database server. The next lesson looks at the similarities between OS tuning and database tuning.