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Multi Valued Dependencies(MVD)  satisfied by relation R(A,B,C) with tuples: (a1,b1,c1),(a1,b1.c2), (a2,b1,c1), (a2,b1,c3)

A⇢⇢B

B⇢⇢A,   BC⇢⇢A, B⇢⇢AC

in Databases by Junior (867 points) | 427 views
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this condition should hold for MVD

A relation R is in 4NF if for all MVD in D+ of the form A->>B at least one of the following hold

A ->> B is a trivial MVD
A is a superkey

but  I am getting confused with  tuples .can someone help me with it

1 Answer

+1 vote

B⇢⇢A, is wrong (a1,b1,c1) and (a2,b1,c1) prove this  //For same B value different A value

BC⇢⇢A is wrong (a1,b1,c1)and(a2,b1,c1) prove this ////For same B,C values different A value

B⇢⇢AC is wrong (a1,b1,c1)and(a2,b1,c1) prove this //For same B value different A, C values

A⇢⇢B is right answer

by Boss (32.9k points)
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You are showing for FD not MVD.
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