User`s guide

7
Tuning Oracle Database 7-1
7 Tuning Oracle Database
Careful tuning can dramatically increase the speed of an Oracle database. This chapter
describes how you can monitor and tune the system for optimal performance of Oracle
database. For a general discussion of performance and tuning issues, refer to Oracle
Database Administrator's Guide and Oracle Database Performance Tuning Guide.
This chapter covers BS2000 specific tuning parameters.
You should always tune Oracle database. In addition, you may need to fine tune or
reconfigure the BS2000/OSD operating system to achieve optimal performance, or to
support more users than the basic configuration enables.
7.1 BS2000/OSD-Specific Parameters
This section describes ORAENV environment variables for BS2000/OSD-specific Oracle
Database performance tuning.
7.1.1 Task Priority
Apart from generic or BS2000/OSD-specific Oracle Database tuning options, the
BS2000/OSD priority of Oracle Database tasks at run-time, and their run-time priority
balance, can have a lot of influence on the overall throughput and the time delays
experienced.
Initially, all foreground (network server) and background tasks have the same
run-time priority, as specified by the
ORAENV environment variable, BGJPAR . Server
tasks automatically become TP tasks, and the background tasks also switches to TP
mode, if the
JOIN entry permits this.
Both before and while changing run-time priorities, you should use SM2 to investigate
task behavior and possible bottlenecks. There is no simple rule that says that certain
tasks always have a high priority.