Sometimes performance can go badly wrong if SQL Server has an imperfect index for an query.

In this session, I show you a query whose performance regresses after you add a nonclustered index. Your challenge is to figure out why the query got slower.

Try your hand at speeding up the query by tuning the TSQL. Afterward, I explore the query execution plan with you and walk you through multiple potential solutions, showing the pros and cons of each one.