Craig Shallahamer's Blog
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You were brought to this page based on an internet search
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The text below is an except from the book,
Oracle Performance Firefighting, written by
Craig Shallahamer of
OraPub, Inc.
Figures and tables are not included on this page, only their reference.
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©2009, 2010 by Craig Shallahamer. This is copyrighted material.
Please—Out of respect for those involved in the creation of the book and also for
their familes, we ask you to respect the copyright both in intent and deed. Thank you.
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<p>Figure 2-14. Various levels of Oracle-focused time classification. The contents could be the result of a one-hour snapshot of all Oracle activity or the result of profiling a specific Oracle transaction. There are numerous classification schemes. The schemes shown here are exceptional for firefighting purposes. When combined with a response-time curve, the communication impact is phenomenal.
p><p>Here, I'll introduce queue time classification and service time classification, discussing how these classifications can be used and their data sources. You'll find more details about these topics in Chapter 5.
p><p>The objective with time classification is to improve our diagnosis and the ability to communicate the results of our analyses. Use just enough complexity to get the job done. In most cases, four or five queue time classifications are all that are needed. One level up from the wait events themselves, I typically use only three classifications: other, IO reads, and IO writes. If the issue is a combination of similar other category wait events, I'll collapse those into a single "sub-other" category. For example, in Figure 2-14, notice that I broke down the other category into latching and non-latching. With just a few categories, I am able to pinpoint the problem, perform an ORTA, and complete a 3-circle analysis, and I can communicate the results to both technical and nontechnical people. All queue time information was gathered from the Oracle wait event views.
p>
©2009, 2010 by Craig Shallahamer. This is copyrighted material.
Please—Out of respect for those involved in the creation of the book and also for
their familes, we ask you to respect the copyright both in intent and deed. Thank you.
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