Work performed by the application:
• Getpages
• Fetches
• I/Os
Class 1 elapsed time:
• Ratio compared to class 2 elapsed time
Class 2 elapsed time (online transactions):
• .050 seconds
• .100 seconds
• .500 seconds
Performance is relative. What are your expectations? Are they reasonable? What constitutes good performance? What is a reasonable amount of work for an online transaction? How do we characterize this?
Many well designed online transaction applications have average elapsed times of less than .020 seconds, and provide true sub-second response time to the end user. However, applications like this are becoming exceedingly rare in today’s environment of bloated application code, poorly designed databases, and poorly coded SQL.
We will try to address what is good, what is reasonable, and what basic metrics indicate that performance is poor or marginal. Having identified that which is poor, we will try to provide some approaches to make things better.