normalization vs de-normalization ?

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normalization vs de-normalization ?

fearghalreilly

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Points: 122
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January 9, 2013 at 8:57 pm

#272654

In a recent test i was asked this question
when considering normalization vs de-normalization which of the following statements are correct?
A)normalizations speeds up data retrieval at the expense of data modifications
B) de-normalization speeds up data modifications at the expense of data retrieval
C)normalization is the process of putting one fact in numerous places
D)de normalization is the process of putting one fact in one place
E)none of the above

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Michael Valentine Jones SSC Guru Points: 64818 More actions · Answer 1

Michael Valentine Jones

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Points: 64818

January 9, 2013 at 9:07 pm

#1575563

So what did you answer?

What do you think the answer is?

fearghalreilly SSC Enthusiast Points: 122 More actions · Answer 2

i went with answer B but not fully sure if it was the correct decision ....

Lynn Pettis SSC Guru Points: 442467 More actions · Answer 3

I may be wrong (meaning I misunderstood the answers), but I would go with E (None of the above).

Orlando Colamatteo SSC Guru Points: 182276 More actions · Answer 4

Looks like A and B are polar opposites, as are C and D, so if only one choice could be correct then I would also go with E.

There are no special teachers of virtue, because virtue is taught by the whole community.
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Gail Shaw SSC Guru Points: 1004504 More actions · Answer 5

Where are these test questions from?

Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

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Grant Fritchey SSC Guru Points: 398679 More actions · Answer 6

I'm not comfortable with any of those answers. A is somewhat true, but so is B. I'd have to choose E if pushed, but I'd want to have a long discussion about it. This test seems seriously messed up. What's it for?

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Jeff Moden SSC Guru Points: 1003853 More actions · Answer 7

I'm with Gail... this type of post seems to be becoming a habit with you. Where are these questions coming from? If they're coming from a MS test, I'd like to remind you that you agreed not to disclose the content of the test and you should stop posting them NOW.

--Jeff Moden

RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
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Create a Tally Function (fnTally)

Lynn Pettis SSC Guru Points: 442467 More actions · Answer 8

If these questions are from a MS test, shoot the test writer. None of the answers really make sense.

Orlando Colamatteo SSC Guru Points: 182276 More actions · Answer 9

Agreed, not about shooting the test writer but about the nonsensical options. You literally have to rule out all the real choices based on how ambiguous they are. "Compare and contrast normalization and de-normalization with respect to data modifications and the expense of data retrieval."

Now that's a solid question, albeit that approach tends to fall down when writing a multiple choice exam 😀

There are no special teachers of virtue, because virtue is taught by the whole community.
--Plato

Jeff Moden SSC Guru Points: 1003853 More actions · Answer 10

opc.three (1/10/2013)
Agreed, not about shooting the test writer but about the nonsensical options. You literally have to rule out all the real choices based on how ambiguous they are. "Compare and contrast normalization and de-normalization with respect to data modifications and the expense of data retrieval."
Now that's a solid question, albeit that approach tends to fall down when writing a multiple choice exam 😀

Did you see the other question concerning the model database? Nah... shoot the test writers.

--Jeff Moden

RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)

Orlando Colamatteo SSC Guru Points: 182276 More actions · Answer 11

No, please share. Nothing like a good witch hunt on a Thursday morning.

There are no special teachers of virtue, because virtue is taught by the whole community.
--Plato

fearghalreilly SSC Enthusiast Points: 122 More actions · Answer 12

the test was for my semester 3 exams in college. These 2 questions that i posted didnt make much sense to me so I just wanted to know what others thought

Abu Dina SSChampion Points: 14155 More actions · Answer 13

fearghalreilly (1/9/2013)
i went with answer B but not fully sure if it was the correct decision ....

Sorry to say that you went for the wrong option!

B) de-normalization speeds up data modifications at the expense of data retrieval

When you de-normalise the data you're going to re-introduce some form of data redundancy. Which means modification would be applied to more rows (as data is now duplicated).

On the other hand, data retrieval would be faster when accessing correctly indexed de-normalised data.

BTW, when I read this earlier today I went for option E but like the rest I chose E because I didn't feel comfortable with the other options.

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