Creating an index seems to be a silver bullet for optimizing a performance of a query. If this is true, then most of performance problems seems to go away, but they exist. And there are lots of cases when creating yet another index doesn’t help. When do indexes help and when do you need to just take a different approach – rewriting the query for removing a bad coding patterns. In this session I will show you when to decide to create an index and which query patterns don’t benefit from indexes. You will see some reason of the plan warnings, cardinality errors, and how to avoid them.