Databases Reference
In-Depth Information
Tuning at the disk level and strategies to
distribute Oracle files
There are many Oracle background and foreground processes involved in a database
instance; each of them specializes in a certain operation. In this recipe we will see what
operations are executed by each process and what type of interaction takes place between
files. On this basis, we will establish a strategy to distribute the Oracle files on different disks
to help improve performance.
In
Chapter 9
,
Tuning Memory
, we have seen that the Oracle
database uses different O/S processes on *nix machines,
and different threads inside the same process on Windows
machines, to obtain the same functionalities. In this chapter,
when we refer to processes, we are talking about either *nix
O/S processes or Windows threads.
Getting ready
To monitor and diagnose I/O performance issues, we need to enable timed statistics in the
database, by setting the appropriate initialization parameter:
ALTER SYSTEM SET TIMED_STATISTICS = TRUE;
Without enabling this parameter we will not be able to see, in the statistics, the time required
to complete an I/O operation; this value is needed to tune the I/O subsystem.
An appropriate Oracle Tuning Management Pack license is required.
How to do it...
The following steps will show how to destribute Oravle files to increase performance:
1.
Connect to the database as
SYSDBA
:
CONNECT / AS SYSDBA
