Tracing CBO Decisions, Hints, and Query Transformations Using 10053
Stelios Charalambides · Apress eBooks · 2017
The Oracle query optimizer is an amazing piece of code, developed and improved over the years to generate execution plans that are both easy to generate and that run fast. The optimizer uses a number of “tricks” along the way to improve the speed of execution and implements the execution plan in a way that gives the same results as your unmodified SQL. These “tricks” (or heuristics) sometimes include query transformations. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.