How Skewness Can Make Your Execution Times Variable
Stelios Charalambides · Apress eBooks · 2013
Skewness is one of those topics that for some reason is often ignored, or misunderstood. Skewness is an important part of data handling for the cost-based optimizer. It makes a difference as to what the optimizer decides to do. It is so important that Oracle created new features such as Adaptive Cursor Sharing just to handle the consequences of skewness.