Excellent Optimizer Statistics articles
Posted by John Hallas on April 12, 2012
For anybody who is interested in reading about optimizer statistics and gaining a clear understanding on what they can do and how they can be managed then I suggest reading the following two white papers
Part 2 contains the best, most easily understood explanation of the problems with bind variable peaking and how they were addressed by using adaptive cursor sharing that I have seen.
Overall both documents are well written with good explanations and diagrams and I think anybody who has any interest in the Oracle Database engine and the tuning of databases for both consistency and performance should make these articles a must read.