Plansplaining, part 12. Foreign keys, part 1
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Welcome to part twelve of the plansplaining series, where I’ll discuss foreign keys in the context of execution plans. And just to be clear, this is not about how foreign keys and other constraints can be used to simplify execution plans and speed up query executions. That is documented in so many places that I trust you already know how important those constraints are. No, today we’ll look at the extra work that SQL Server needs to do to ensure that your changes don’t violate any of your foreign key constraints. Sample tables I will use a very simple scenario…
