Oracle Consulting Oracle Training Oracle Support Development
Home
Catalog
Oracle Books
SQL Server Books
IT Books
Job Interview Books
eBooks
Rampant Horse Books
911 Series
Pedagogue Books

Oracle Software
image
Write for Rampant
Publish with Rampant
Rampant News
Rampant Authors
Rampant Staff
 Phone
 800-766-1884
Oracle News
Oracle Forum
Oracle Tips
Articles by our Authors
Press Releases
SQL Server Books
image
image

Oracle 11g Books

Oracle tuning

Oracle training

Oracle support

Remote Oracle

STATSPACK Viewer

Privacy Policy

 

 
 

High Av Rd(ms)

Article by Rampant Author Brian Carr

If you are seeing high Average Disk Read times in your Oracle AWR Report read this tip.

High Average Disk Read times can be seen under the Tablespace IO Stats section of the AWR Report. When you see Av Rd(ms) of greater than 7 ms you may have an issue that requires further investigating. This could mean your system is experiencing extremely slow Avg Read times from the disk subsystem.

Recommendation:
In addition to SQL tuning of high-impact statements, the disk subsystem may need tweaked. This following disk setup would help with scattered and sequential disks reads. Additionally it would allow log switches to occur more rapidly.

Some considerations to make when purchasing an alternative storage solution are:

  • At least 512MB cache on Raid controllers, BBWC (battery backed write cache)
  • RAID Setup must be RAID 10 (Oracle Best Practice) - Don't let your SAN Admin tell you its too expensive. So is your time and all the users who are going to suffer from a poor disk setup....
  • Number of spindles (the more the better)

 

 

 

   

 Copyright © 1996 -2016 by Burleson. All rights reserved.


Oracle® is the registered trademark of Oracle Corporation. SQL Server® is the registered trademark of Microsoft Corporation. 
Many of the designations used by computer vendors to distinguish their products are claimed as Trademarks