I still remember the day a colleague handed me The Fish Book and simply told me to read it. This was in the early years of my Oracle journey, and I was getting deep into Oracle performance analysis and loving it. The book was actually titled System Performance Tuning, but since it had a picture of a big swordfish on the cover, we always called it The Fish Book. That night I started reading the book, and I was intrigued. It gave me an entirely new perspective on performance analysis. I began to discover that what was happening to the operating system correlated with what was happening with Oracle. It was like getting another opinion or having someone review my work. From that point on, every time I talk, teach, and write about Oracle analysis, you can expect it to be confirmed from an operating system perspective as well. The operating system analysis has such a profound impact on performance firefighting that it's one of the three circles in OraPub's 3-circle analysis.

This chapter is not your typical operating system chapter. Most people reading this book already have a pretty good understanding of how to install, upgrade, and administer Oracle on a host operating system. You know the typical commands to find files-do some awk'ing and grep'ing-and how to perform standard administration tasks. But I will go beyond issuing commands and understanding syntax.

Here, I focus on how to quickly determine the operating system's bottleneck using standard, freely available tools and how to ensure what you're seeing in Oracle matches what you're seeing from an operating system perspective. I will show you how to hook this altogether using the OraPub 3-circle analysis method (introduced in Chapter 1). I want you to be able to stand in front of your operating system administration team and confidently explain to them where the operating system bottleneck resides, how you discovered it, how Oracle is involved, and what can be done to resolve the problem from three different perspectives.