MVP Magi Naumova is back, and this time the focus is on query tuning. Food and drinks will be provided at 1700, and Magi's session will start around 1720. Welcome!
Query tuning when indexes cannot help with Magi Naumova
Creating an index seems to be a silver bullet for optimizing the 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 bad patterns. In this session I will show you how to decide to create an index or not, 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.