Q.1.
A candidate key must uniquely identify each row.
Q.2.
Well-structured relations encourage anomalies of data.
Q.3.
A foreign key may be null and still adhere to the referential integrity constraint.
Q.4.
If a relation is in third normal form, it does not need to be in second normal form.
Q.5.
The primary key of the new relation in a many-to-many relationship is a composite key comprised of the primary keys of each of the binary entities.
Q.6.
A null value is assigned when no other value applies.
Q.7.
A synonym is two or more attributes that have different names but the same meaning.
Q.8.
The primary key in a relation does not need to be underlined.
Q.9.
In a 1:M relationship, the primary key on the one side migrates to the many side to become the foreign key on the many side.
Q.10.
An enterprise key is a primary key whose value is unique for a given relation.
Q.11.
Normalization is a formal process for deciding which attributes should be grouped together in a relation.
Q.12.
A composite attribute does not get mapped into a relation.
Q.13.
A relation is a two-dimensional table.
Q.14.
Weak entities do not get mapped into a relation.
Q.15.
A relation has which of the following properties?
Q.16.
When mapping a ternary relationship with an associative entity into a relation which of the following is true?
Q.17.
A primary key may be null.
Q.18.
When mapping a regular entity into a relation which of the following is true?
Q.19.
When mapping a supertype/subtype relationship which of the following is true?
Q.20.
When mapping a multivalued attribute into a relation which of the following is true?