edited by
6,582 views
7 votes
7 votes

Every time the attribute A appears, it is matched with the same value of attribute B but not the same value of attribute C. Which of the following is true?

  1. A -> (B,C)      
  2. A -> B, A ->> C      
  3. A -> B, C ->> A        
  4. A ->> B, B -> C
edited by

1 Answer

Best answer
13 votes
13 votes
the option b is correct . there is just a small definition of multivalue dependencies which . if a->> c is a dependency it means for a ,c has more than one value.

here it is saying whenever a appears b has same value which is true in case of functional dependency . if a->b exist for every a if repeats there should be same b . so a-.b exist here and it is clearly saying c is not same which means for same a it contains multipule value of c. so answer is b .
why not c ??

just consider the case
a is 1

and for c

A       C

1       3

1        4

now u can see that for a we have multipule value of c but c does not have multiple values for a . so we cannot say c->>a . but we can say a->>c. and question is saying c can take different value not a .
Answer:

Related questions

10 votes
10 votes
4 answers
1
go_editor asked Jul 1, 2016
8,336 views
Consider the following tableThe table is in which normal form?First Normal FormSecond Normal FormThird Normal Form but not BCNFThird Normal Form and BCNF
5 votes
5 votes
2 answers
3
6 votes
6 votes
2 answers
4
Anu asked Jun 28, 2016
6,536 views
An aggregation association is drawn using which symbol?A line which loops back on to the same tableA small open diamond at the end of a line connecting two tablesA small ...