.A primary key which is imported from another table is called a foreign key.b.Foreign key is essential for each tuple.c.Composite attribute can not divide to sub partsd.In a formal relational model data are stored in tables.e.Age is derived by date of birth attribute
Question
.A primary key which is imported from another table is called a foreign key.b.Foreign key is essential for each tuple.c.Composite attribute can not divide to sub partsd.In a formal relational model data are stored in tables.e.Age is derived by date of birth attribute
Solution
a. True. A primary key that is used in another table to reference the original table where it is used as a primary key is called a foreign key.
b. False. A foreign key is not essential for each tuple. It is used for linking two tables.
c. False. A composite attribute can be divided into smaller sub-parts. For example, a 'Name' attribute could be divided into 'First Name' and 'Last Name'.
d. True. In a formal relational model, data are indeed stored in tables. These tables are also known as relations.
e. True. Age can be derived from the date of birth attribute by calculating the difference between the current date and the date of birth.
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