Dal portale Simple-Talk (Red-Gate) è possibile scaricare gratuitamente l’eBook: Complete Showplan Operators di Fabiano Amorim.
Il libro tratta i più importanti operatori logici coinvolti nei piani di esecuzione, spiegandone il funzionamento e i motivi che spingono Query Optimizer alla scelta di un operatore rispetto agli altri.
Riporto di seguito la prefazione di Grant Fritchey.
Preface
Writing good TSQL code is not an easy task. Then you submit the code to the query optimizer and strange things happen. The one good view you have into what the optimizer decided to do is provided by the execution plans. Understanding execution plans is a lot of work. Trust me on that. What you need to really understand your queries is as much knowledge as you can get. That’s where this excellent collection of articles on some of the more common execution plan operators comes in.
Fabiano Amorim has taken the time to reallv drill into the behavior of a small set of execution plan operators in an effort to explain the optimizer’s behavior. He’s explored why things happen, how you can change them, positively or negatively, and he’s done it all in an approachable style. You want information and knowledge in order to achieve understanding.
When I wrote my book on execution plans, 1 really did try to focus on the plan as a whole So while I spent time talking about individual operators, what they did, and why they did it, 1 was frequently not as interested in discussing everything that an individual operator might do once I had established their role in a given plan. Having someone like Fabiano come along and go the opposite route, sort of ignoring the whole plan in an effort to spend time exploring the operator, acts to fill in gaps. Where I tried to teach how to read an execution plan, Fabiano is trying to teach what a given operator does. It’s all worth- while and it all accumulates to give you more knowledge.
Il codice utilizzato negli esempi è scaricabile, molto interessanti anche i link alle risorse esterne (articoli, video, ecc…) che si trovano, di volta in volta, annegati nelle pagine del libro.
Buona lettura!