![]() |
![]() |
![]() |
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
![]() |
![]() |
To access the contents, click the chapter and section titles.
Oracle Performance Tuning and Optimization
Both the data files and the indexes should be striped over as many disk drives as necessary to achieve optimal I/O rates on those disks. From Chapter 14, Advanced Disk I/O Concepts, remember that you can only push a disk drive to a maximum random I/O rate. When you use a disk array, the data is automatically striped across all the disk drives; therefore, it is necessary to create only one tablespace and table for all your data. You do not even have to put indexes into another tablespacealthough I recommend doing so for other reasons (such as monitoring and maintenance). With traditional disks, it is difficult to manage hundreds of data files and disks; with a disk array, you can manage hundreds of disks with just a few data files. Of course, Oracle has a 2 gigabyte limitation on the size of a data file, but this is easily resolved by creating a data file for every 2 gigabytes of space you need. The data files can all reside on the same disk array volume. If you use a disk array, many of the management tasks and load balancing tasks are greatly simplified. With the disk array, you also have the option of using fault tolerance without affecting system performance. Of course, using fault tolerance requires significantly more disks. I recommend that you use a disk array if possible. Software striping is fine, but if your system is under heavy loads (as is typical in a system used for BLOB data), you can achieve better performance by offloading the striping overhead to a hardware RAID controller. Hardware ConsiderationsWhen choosing hardware to use for a system used for BLOB data, consider these factors:
Because this type of data access does not typically involve heavy CPU activity, you may not see any benefit from multiple CPUs. It is much more important to have a system that can handle extreme amounts of I/O and network processing. This is not to say that the CPU activity will not be high, but the BLOB system is not as CPU bound as is a typical OLTP or DSS system. With this type of access to the disks, you can benefit from a disk array. I prefer hardware striping to OS striping because it does not incur any additional overhead for the operating system and does not take up valuable CPU cycles. If hardware striping is not available, OS striping is adequate. Because network traffic is very high, you must have a sufficient network bandwidth to handle the load. A high-speed network solution such as 100Base-T or fiber optics can benefit the overall performance of the system. Tuning ConsiderationsThe system used for BLOB access is designed to give optimal access to large amounts of data as quickly as possible. It is also frequently a requirement that the data streams be continuous for both video and audio data. You may have to tune both Oracle and the server operating system. The following sections look first at Oracle and then at the server operating system. Oracle TuningCarefully analyze these things to determine whether adjustment to these parameters is necessary:
Pay particular attention to these areas when tuning a system for BLOB access. Probably the area that requires the most attention is the I/O subsystem. By optimizing the I/O subsystem, you will see performance increases.
|
![]() |
Products | Contact Us | About Us | Privacy | Ad Info | Home
Use of this site is subject to certain Terms & Conditions, Copyright © 1996-2000 EarthWeb Inc. All rights reserved. Reproduction whole or in part in any form or medium without express written permission of EarthWeb is prohibited. |