See Our team

Wondering how we keep quality?

Got unsolved questions?

Ask Questions

Engineering
GATE
CBSE
NCERT
Psychology
English
Computer
Constitution
Astrology
Yoga
Economics
Physics
Biology
Electronics
Microprocessor
Career
Interview
Anatomy
Botany

## Explain multivalued dependency and fourth normal form,with an example .Database Management Systems - 10CS54 VTU notes (JULY 2013 / July 2015)

Explain with example?By:anonymousguy7799

Taged users:

Likes:

Be first to like this question

Dislikes:

Be first to dislike this question

Talk about thisDelete|Like|Dislike|

## Answers

Multivalued Dependencies and Fourth Normal Form (4NF) 4NF associated with a dependency called multi-valued dependency (MVD). MVDs in a relation are due to first normal form (1NF), which disallows an attribute in a row from having a set of values. MVD represents a dependency between attributes (for example, A, B, and C) in a relation, such that for each value of A there is a set of values for B, and a set of values for C. However, the set of values for B and C are independent of each other.MVD between attributes A, B, and C in a relation using the following notationA - > - > B (A multidetermines B) A - > - > CFormal Definition of Multivalued Dependency A multivalued dependency (MVD) X Y specified on R, where X, and Y are both subsets of R and Z = (R – (X Y)) specifies the following restrictions on r(R) t3[X]=t4[X]=t1[X]=t2[X] t3[Y] = t1[Y] and t4[Y] = t2[Y] t3[Z] = t2[Z] and t4[Z] = t1 [Z]

Nikhil-bharadwaj

Likes:

Be first to like this answer

Dislikes:

Be first to dislike this answer

Talk about this|Once you have earned teacher badge you can edit this questionDelete|Like|Dislike|

------------------------------------

## Can you help us to add better answer here? Please see this