Call (800) 766-1884 for Oracle support & training
Free Oracle Tips

Oracle Consulting Support
Oracle Upgrades
Use New Oracle Features
Oracle Replication Support
Oracle Training
Remote Oracle DBA
System Documentation
Oracle Tips
Oracle Performance

Free Oracle Tips



BC Oracle tuning

Oracle training

Oracle support

Remote Oracle



  Oracle Tips by Burleson

SSD Benchmark Hypothesis

Now that the issues surrounding SSD in an Oracle environment have been covered, one can form a hypothesis about the results of the benchmark tests. 

The central question of this study is to determine the benefit of SSD for Oracle under these conditions:

  • No SSD with a super large Oracle data buffer: This can minimize PIO with only one physical read into the data buffer, but LIO overhead will be revealed.

  • SSD with a tiny Oracle data buffer: This makes PIO faster but will have repeated LIO overhead as data blocks are aged out of the Oracle data buffer.  The LIO overhead would be expected to be huge, with high latch contention, buffer busy waits , and free buffer waits.

  • SSD for files with large Oracle Data buffer cache: This is duplicating RAM, but it would relieve the LIO issue.

It is now possible to postulate about the benchmark results. If it is assumed that SSD is far faster for PIO, the issue of duplicate Oracle activity remains.  At PIO time, the data block must still be read into the db_cache_size , and then a consistent get is required to deliver the data block to the requesting program.

RAM resources, therefore, appear to be better allocated directly to the db_cache_sizeinstead of using the RAM with SSD.


The above book excerpt is from:

Oracle RAC & Tuning with Solid State Disk

Expert Secrets for High Performance Clustered Grid Computing

ISBN 0-9761573-5-7

Donald K. Burleson & Mike Ault


Oracle performance tuning software 

Oracle performance tuning book


Oracle performance Tuning 10g reference poster
Oracle training in Linux commands
Oracle training Excel
Oracle training & performance tuning books



Copyright © 1996 -  2014 by Burleson. All rights reserved.

Oracle® is the registered trademark of Oracle Corporation. 

Hit Counter