Query Optimizer Internals : Traceflag fun
The query optimizer is at the heart of SQL Server. Without it SQL Server would be a vastly inferior product, queries would have to be manually tuned at each and every turn, and generally speaking, the optimizer protects us from the complexities and mechanics involved. Much of the optimizer's internal workings are hidden from the user, but can be revealed by using a selection of undocumented trace flags to gain further knowledge and insight into how your queries and data are processed to create a plan.
This session will be a deep dive into the optimizers' internals and not for the feint of heart.