Skip Headers
Oracle® Database Administrator's Reference
11g Release 2 (11.2) for Linux and UNIX-Based Operating Systems

Part Number E10839-02
Go to Documentation Home
Home
Go to Book List
Book List
Go to Table of Contents
Contents
Go to Index
Index
Go to Master Index
Master Index
Go to Feedback page
Contact Us

Go to previous page
Previous
Go to next page
Next
View PDF

D Managing Input Output Resources

This appendix explains improvements in the Oracle Database Resource Manager for Oracle Database 10g series. It includes information about the following topics:

D.1 Overview

In Oracle Database 10g, Oracle Database Resource Manager manages the CPU resource among Oracle processes in an instance. However, at times those processes are bound by the input-output. It would be more effective to be able to also manage the input-output bandwidth. The new Input Output Resource Manager feature helps manage dynamic resources involved in handling disk input-output operations.

You can enable Input Output Resource Manager on all platforms on which Oracle runs. It works on small and large database configurations, and on hardware configurations. Further, Input Output Resource Manager scales with both, the number of disks and the additional channel capacity.

Input Output Resource Manager permits you to perform the following tasks:

Enabling Input Output Resource Manager does not cause any significant decrease in performance.

D.2 Requirements

The following is the list of the requirements for Input Output Resource Manager:

D.3 PL/SQL Statement

You can calibrate the input-output capabilities of the storage, by using the following PL/SQL statement:

DBMS_RESOURCE_MANAGER.CALIBRATE_IO()

Input-output calibration involves obtaining the storage's capabilities by issuing an extremely heavy input-output workload.

Storage capability is calculated in terms of how many input-output requests and bytes of input-output can be sustained for each second.

Input-output workload consists of random reads. It uses single database block reads and large reads whose size is determined by the maximum size of input-output that is supported for the host's operating system.

Note:

If you excluded any files from being managed, then the unmanaged files are not used for input-output calibration.

Status and Results View

The input-output calibration procedure returns immediately, however, the results are not available immediately. You must refer to the V$IO_CALIBRATION table for the status and results of input-output calibration.

Table D-1 lists the components of a V$IO_CALIBRATION table.

Table D-1 Components of a V$IO_CALIBRATION Table

Component Description

STATUS

Provides the status of input-output calibration, whether it's in progress or ready. Results are available when the status changes to ready.

START_TIME

Provides the time at which the input-output calibration was initiated.

END_TIME

Provides the time at which the input-output calibration completed.

MAX_IOPS

Provides the maximum number of read requests that can be sustained for each second. The size of the read is specified by the parameter DB_BLOCK_SIZE. The reads are issued so that they are as randomly scattered as possible.

MAX_MBPS

Provides the maximum number of bytes of reads that can be sustained for each second. The size of the read is the maximum possible for the host's operating system platform, which is 1 MB. The reads are issued so that they are as randomly scattered as possible.