Anyone who stares at query plans for a living.
The optimizer has options.
Not every option is optimal.
Optimistic query tuners hope that the optimizer will make optimal choices.
Often, the optimizer will stick an optional operator in a plan that just doesn’t belong.
Sorts, Spools, Lookups, Tops, Aggregates, and Bitmaps can all end up where they don’t belong.
Opt out of bad powerpoint decks with this demo-only session!
Joe Obbish and Erik Darling will show you when the optimizer’s optics might require a trip to the optometrist.
Why I Want to Present This Session:
Look, you’ve been watching the same query tuning session for years.
There’s a function, there’s a table variable, there’s parameter sniffing, there’s a cursor, and oh lord, something just wasn’t SARGable.
But what happens when you’ve already fixed that stuff, and you’ve still got problems?