Discuss the differences between the candidate keys and the primary key of a relation. Explain what is meant by a foreign key. How do foreign keys of relations relate to candidate keys? Give examples to illustrate your answer.
What will be an ideal response?
The primary key is the candidate key that is selected to identify tuples uniquely within a relation.
A foreign key is an attribute or set of attributes within one relation that matches the candidate key
of some (possibly the same) relation.
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You are preparing to give a presentation at a client’s location using your mobile device and a large screen TV. You have successfully connected to the company’s guest Wi-Fi network, and you tap the screen mirroring option on your device but cannot locate an available TV, monitor, or projector. The previous presenter finished her presentation a few minutes earlier and had no issues using the TV. Which of the following is the most likely reason for this behavior?
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