Performance Tuning - Professional SQL Server 2005 Performance Tuning - page 14

serious problems. First of all you are getting 60 percent of the transactions with almost double the CPU
load. That's a great indication you either changed a query somewhere, you are getting a sub-optimal
execution plan, your indexes are shot, you reached some size threshold on one of the tables, or some
other bottleneck is occurring.
Without the baseline, 50 transactions per second is just a talking point with no point of reference to
compare to. With the baseline, 50 transactions per second is the start of a meaningful investigation into a
performance issue.
Part III of the topic covers some of the basic techniques for monitoring and baselining
system performance.
Summary
Performance tuning isn't an art, it's a science. In this chapter you learned about the science of perfor-
mance tuning. You started with the steps in the methodical approach to performance tuning: starting
from the problem statement, moving onto the plan of attack, data collection, followed by data analysis,
and then repeating until you achieve your goal. You were introduced to some of the many tools available
to assist with performance tuning. Some of these are covered in more detail throughout the remainder of
this topic. In the next chapter you will learn about using Performance Monitor to look at server resources.