Show Bid Request
General Questions
Bid Request Id: 39154
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Posted by: |
egypt123 (2 ratings)
(Software buyer rating 9.5 )
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Non-action Ratio: |
Very Good - 0.00%
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Posted: |
Dec 9, 2002
10:36:26 PM EDT
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Bidding Closes: |
Dec 11, 2002
4:50:00 PM EDT
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Viewed (by coders): |
98 times
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Deadline: |
12/11/2002 5:00:00 PM
TIME EXPIRED
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Description:
Just Answer The Following Questions:
1- Define Armstrong 's Axioms, and explain the statment that "they are a sound and complete set of rules for FD inferences."
2- What is the dependency closure F+ of a set of F of FDs? What is the attriubte colsure X+ of a set of attriubtues X with respect to a set of FDs F?
3- Consider the relation R and its functional dependencies d1, d2, d3, and d4.
R = ( A, B, C, D, E, F)
(d1) : B -> C
(d2) : D -> F
(d3) : AB -> E
(d3) : C -> D
Is the set of attributes {A, B, C} a superkey?
Is the set of attributes {A, B, C} a candidate key? If not identify at least on candidate key.
4- Show that each of the following are not valid rules about functional dependencies by giving example relations that satisfy the given dependencies but not the one that allegedly follows.
a) If A -> B the B -> A.
b) If AB -> C and A -> C, then B -> C.
c) If AB -> C, then A -> C or B -> C
5- Consider a relation with schema R(A,B,C,D) and functional dependencies AB ->C , C -> D, and D -> A.
A) What are all the nontrivial functional dependencies that follow from the given dependencies? (compute the closure of given set of functional dependencies F+)
B) What are all the candidate keys of R?
C) What are all the superkeys for R that are not a candidate key?
6- Repeat the above exercise for the following schema and functional dependencies :
T(A, B, C, D) with functional dependencies AB -> C, BC -> D, CD -> A, and AD -> B.
7- Consider the Set F of functional dependencies on the set of attributes ABCDE:
F = {B -> CD, AD -> E, B -> A}
a) Is BA a Superkey? Is it a candidate key? Display your analysis in detail
b) Compute F+.
Deliverables:
1)Just need the right answers to the questions in word document.
2) Complete ownership and distribution copyrights to all work purchased.
Platform:
Windows version of Microsoft Word
Must be 100% finished and received by buyer on:
Dec 11, 2002 5:00:00 PM EDT
Deadline legal notes: All times are expressed in the time zone of the site EDT (UT - 5). If the buyer omitted a time, then the deadline is 11:59:59 PM EDT on the indicated date.
Special Conditions / Other:
please have completed by weds 12/11/2002 by 5 pm eastern standard time
Additional Files:
This bid request includes IMPORTANT additional attached files. Please download and read fully before bidding.
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Bidding/Comments:
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| Name |
Bid Amount
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Date |
Coder Rating |
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This bid was accepted by the buyer!
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$20 (USD)
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Dec 9, 2002
11:25:01 PM EDT
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9.33
(Superb)
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I will submit your assignment on time .
If you are interested then let me know .
Thankyou !
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