Mastering Performance with Extended SQL Trace
24 February 2011
Oracle's extended SQL trace data stream contains a linear sequential record of every database call and every operating system call that the Oracle kernel executes in response to the code that you write. The trace file contains timings that enable you to precisely measure how long your code takes to run and why. The detailed information about individual database calls and operating system calls is vital to building scalable applications (as well as troubleshooting them in production). The information in there is a gold mine, and some of it is available nowhere else.