Database management system a What set results if I JOIN two

Database management system:

a. What set results if I JOIN two tables together but fail to specify the key/fkey booleans? (Why?)

b. What is a partial dependency and how would I find it on the FD diagram?

c. What are the goals of normalization?

Solution

a)))))))))))

we join two or more tables inorder to get combination the rows from those two or more tables and it is based on the the coomon attribute or field or column in between the tables.In general we use sql inner join to join the tables when we meet the condition.

b)))))))))))))))

A functional dependency X Y is said to be a full functional dependency if it holds the fallowing scenario.if we remove any one of the attribute suupose that is A from X that means: the dependencycannot exists between X and Y.

A functional dependency X Y is said to be a partial dependency if it holds the fallowing properties:if some attribute say A then if suppose A X is removed from X then also the dependency exists between X and Y: that is, for some A X, (X – {A}) Y.

c))))))))))))

the main gaol or aim of normalization is to get free from redundancy of the data in the relational tables as well as maintainning consistancy in the relational database.

Normalization is the simple technique that is used to clear or remove the redundant or repeated data from the relational tables by splitting the tables into smaller tables.