Erik Darling doesn’t need your costs:
Costs are okay for figuring out why SQL Server’s cost-based optimizer:
– Chose a particular query plan
– Chose a particular operator
Costs are not okay for figuring out:
– Which queries are the slowest
– Which queries you should tune first
– Which missing index requests are the most important
– Which part of a query plan was the slowest
Yep. And read on for more information.