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Consider the following table

Department Job Part
d1 j1 p1
d1 j1 p2
d1 j2 p1
d1 j2 p2
d2 j3 p2
d2 j3 p4
d2 j4 p2
d2 j4 p4
d2 j5 p2
d2 j5 p4
d3 j2 p5
d3 j2 p6

The above table has multivalued dependencies as

(A) Department \twoheadrightarrow Job
(B) Department \twoheadrightarrow Part
(C) Both (A) and (B)
(D) None of these

Shubham Madheysia @mad_hey_sia
31 Oct 2016 10:58 am

if we consider seond last tuple as t2,t3 and last tuple as t1,t4 then MVD(Department, Job) is satisfied. Similarly taking seond last tuple as t1,t3 and last tuple as t2,t4 then MVD(Department, Part) is satisfied. 

Option C should be answer.

Ranita Biswas @ranita
1 Nov 2016 11:02 pm

Yes, you are right. When checking for MVD, it's not necessary for t1, t2, t3, t4 to be separate rows. @pritam please correct it in the video.

Pritam Prasun @pritam
2 Nov 2016 01:00 pm

Yes, I will update the video ASAP.

Thank You @mad_hey_sia @ranita

Mohd Asad @mohdasad
8 Nov 2016 12:44 pm

will it be right to say that a single tuple can be taken as t1,t2,t3,t4 ??@ranita mam.

Ranita Biswas @ranita
8 Nov 2016 04:44 pm

Yes, t1, t2, t3, and t4 are not necesarily distinct, they can reprsent a single row as well.

k.nikhil kumar @nikhilkolla
4 Nov 2016 08:20 pm

If  x→y, x→z  we call it as MVD

In this question d1→j1 ,d1→j2 then department→job is MVD

AND department→part is MVD. Because d1→p1,d1→p2.

So I think option c is correct.

k.nikhil kumar @nikhilkolla
4 Nov 2016 08:24 pm

If  x→y, x→z  we call it as MVD

In this question d1→j1 ,d1→j2 then department→job is MVD

AND department→part is MVD. Because d1→p1,d1→p2.

So I think option c is correct.

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