Joint Dependency and Multivalued Dependency

1) What is meant by Joint DEPENDENCY in normalization?
2) What is a MULTIVALUED DEPENDENCY? Explain.

Questions by fenum

Showing Answers 1 - 9 of 9 Answers

sravan

  • Dec 29th, 2006
 

u see.....joint dependency means that.........when u decompose tables those decomposed table should satisfy JOIN dependency ...ie., when they are joined they should make the original table without any conflicts.......MULTIVALUED DEPENDENCIES means the fourth normal form.......when a table is in such a way that t1(a)=t2(a)=t3(a)=t4(a);t1(b)=t2(b) and t3(b)=t3(4);t1(c)=t3(c) and t2(c)=t4(c);this can be decomposed again with the 4th normal form.....

  Was this answer useful?  Yes

Athira.m.m

  • Oct 12th, 2015
 

You see joint dependency means that when you decompose tables those decomposed table should satisfy JOIN dependency ie., when they are joined they should make the original table without any conflicts MULTIVALUED DEPENDENCIES means the fourth normal form when a table is in such a way that
t1(a) = t2(a) = t3(a) = t4(a);
t1(b) = t2(b) and t3(b) = t3(4);
t1(c) = t3(c) and t2(c) = t4(c);
this can be decomposed again with the 4th normal form.



  Was this answer useful?  Yes

shivakumar

  • Jan 12th, 2016
 

When you decompose a relation into sub relations and when you assembled those sub relations it should result in original loss-less relation. Such dependency is called join dependency. Example relation R is decomposed into r1, r2.....rn than when you assembled them it should equals to R (without any loss).

  Was this answer useful?  Yes

Give your answer:

If you think the above answer is not correct, Please select a reason and add your answer below.

 

Related Answered Questions

 

Related Open Questions