Can foreign keys hurt query performance

Question

As I understood from this post, there are some scenarios where foreign keys can improve query performance.

I\'ve heard the opposite claim though, that because of refere

Answer 1

if a foreign key is needed for referential integrity then the presence of the foreign key should form the baseline for performance

you might as well ask if a car can go faster if you don't put seats in - a well formed car includes seats as much as a well formed database includes foreign keys