Oracle7 Server Tuning

The Importance of Memory Allocation

Oracle stores information in two places:

in memory

on disk

Since memory access is much faster than disk access, it is desirable for data requests to be satisfied by access to memory rather than access to disk. For best performance, it is advantageous to store as much data as possible in memory rather than on disk. However, memory resources on your operating system are likely to be limited. Tuning memory allocation involves distributing available memory to Oracle memory structures.

Because Oracle's memory requirements vary depending on your application, you should tune memory allocation after tuning your application and your SQL statements based on the recommendations presented in Chapter 7, "Tuning SQL Statements". Allocating memory before tuning your application and your SQL statements may make it necessary to resize some Oracle memory structures to meet the needs of your modified statements and application.

Also, you should tune memory allocation before considering the information in Chapter 9, "Tuning I/O". Allocating memory establishes the amount of I/O necessary for Oracle to operate. This chapter shows you how to allocate memory to perform as little I/O as possible. Chapter 9 shows you how to perform that I/O as efficiently as possible.