palotaiarpad (11/9/2011)

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The space used to store nullable fields is the only bottleneck. I missed it.

lucydickinson (11/9/2011)

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Really enjoyed this question .. pity I got it wrong but I have definitly learnt something!:

L' Eomot Inversé (11/9/2011)

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Good question.

The correct answer rate is still only 9%, which I find surprising.

Mostly a very good explanation, too, but I have one small cavil:

There is an index which supports the foreign key constraint, and indeed you are not permitted to create the foreign key constraint unless that index already exists when you try to create the foreign key; so it's wrong to say there is no such index. However, that index is not part of the table being discussed, but of the referenced table, and it's reasonable to assume that the question is about space for the table being discussed so that space for the index on the referenced table doesn't count, and thus this affects only the explanation and not the answer.

Hugo Kornelis (11/9/2011)

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I must say that the low rate of correct answers surprises me.

Luckily, the text of my question explicitly includes "... used by the table are true". So it is not only, as you say, reasonable to assume that the question is about space for the table being discussed - it is explicitly stated!

codebyo (11/9/2011)

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Wow, very elaborated question.
It made my brain hurt for a second.

I've got 3/4 options right.

I only missed one which should have been basic knowledge to me:

"The amount of space used DOES depend on the fragmentation of the index that supports the PRIMARY KEY constraint."