![]() |
![]() |
![]() |
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
![]() |
![]() |
To access the contents, click the chapter and section titles.
Oracle Performance Tuning and Optimization
Network Packet Size By using larger network packets, you can transmit the same amount of data with fewer packets. Because there is an inherent overhead associated with each network packet, reducing the number of packets enhances the overall performance. The size of the network packets is typically not an OS issue but an issue of the backup software you are using. It may be necessary, however, to increase the maximum allowable network packet size to accommodate your backup software. If you use larger network packets, you can typically use more of the bandwidth of the network. When a typical Ethernet network card wants to transmit on the network, it first checks to see whether there a packet is currently being transmitted. If the network is busy, the card waits a specified period of time and then tries to transmit again. If you use many small packets, it is more likely that the network will be busy than if you use a few large packets; with the larger packets, there is usually more time between transmissions. The efficiency of larger packets provide better performance. If network bandwidth is still an issue, consider adding an isolated segment for backups or going to a faster network controller such as 100Base-T or fiber optics. Backup Software The choice of OS or third-party backup programs can be very important. Dont be influenced solely by how flashy the GUI is or the number of features in the backup software. The features included in many of the backup packages are important but should not overshadow the products performance. The main goal in backing up your database is to protect your data and to disrupt the user community as little as possible. To do this, the backup software should be high performance and reliable. The integrity of your system depends on the reliability of your backups. Measure the performance of your backup software periodically and test the backups to make sure that everything is working properly. The performance of your backup software can depend on the configurability of the product. Make sure that you can adjust the block size of both data reads and tape writes so that you can optimally tune for your particular devices. There have been vast improvements in compression algorithms over the last few years; some of the new techniques can be quite effective in improving both performance and efficiency, as described in the following section. High-Performance Compression Compression techniques have improved significantly in the last few years. This improvement affects both the performance and efficiency of the compression. By using a high-performance compression algorithm in your backup procedure, you can improve the efficiency of the backup. By using a recent version of your backup software, you will most likely take advantage of the most optimal compression techniques. Many of the components of the backup (such as the network or tape device) have a maximum data rate. By using compression to reduce the amount of data to be written to these devices, the entire data file can be written to the device faster. Your performance may suffer if the compression causes you to become CPU bound. If you have a sufficient number of CPUs that are fast enough to keep the tape or network device running at maximum efficiency, compression can be a beneficial part of your backup procedure. You can verify the performance of your CPUs by backing up the same data file both with and without compression and comparing the performance. Keep in mind that many tape devices have hardware compression built in. If you compress the data before sending it to the tape device, the efficiency of the hardware compression may be reduced, nullifying any beneficial effect of OS or software compression. The only way to know whether compression can be beneficial is to try backing up with and without it. Once you have determined the beneficial value of compression, you can concentrate on other areas of enhancement. SummaryThis chapter looked at how backups work in the Oracle system and some of the ways you can enhance the performance of your backups. With mission-critical systems that must be available 24 hours a day, 7 days a week, backup and recovery performance is crucial. By increasing the performance of the backup, you shorten the amount of time that users see some sort of degraded performance caused by the backup.
|
![]() |
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. |