Q: The _________ provides a set of operations that take one or more relations as input and return a relation as an output
A.Schematic representation
B.Relational algebra
C.Scheme diagram
D.Relation flow
Correct Option: BExplanation: Relational algebra
Q: The term _______ is used to refer to a row.
A.Attribute
B.Tuple
C.Field
D.Instance
Correct Option: BExplanation: Tuple is one entry of the relation with several attributes which are fields.
Q: The most commonly used operation in relational algebra for projecting a set of tuple from a relation is
A.Join
B.Projection
C.Select
D. Union
Correct Option: CExplanation: Select is used to view the tuples of the relation with or without some constraints.
Q: For each attribute of a relation, there is a set of permitted values, called the ________ of that attribute.
A.Domain
B.Relation
C.Set
D.Schema
Correct Option: AExplanation: The values of the attribute should be present in the domain.A domain is a set of values permitted.
Q: A ________ is a pictorial depiction of the schema of a database that shows the relations in the database, their attributes, and primary keys and foreign keys.
A.Schema diagram
B.Relational algebra
C.Database diagram
D.Schema flow
Correct Option: AExplanation: Schema diagram
Q: The result which operation contains all pairs of tuples from the two relations, regardless of whether their attribute values match.
A.Join
B.Cartesian product
C.Intersection
D.Set difference
Correct Option: BExplanation: Cartesian product is the multiplication of all the values in the attributes.
Q: The tuples of the relations can be of ________ order.
A.Any
B.Same
C.Sorted
D.Constant
Correct Option: AExplanation: The values only count .The order of the tuples does not matter.
Q: A relational database consists of a collection of
A.Tables
B.Fields
C.Records
D.Keys
Correct Option: AExplanation: Fields are the column of the relation or tables. Records are each row in a relation. Keys are the constraints in a relation.
Q: A domain is atomic if elements of the domain are considered to be ____________ units.
A.Different
B.Indivisbile
C.Constant
D.Divisible
Correct Option: BExplanation: Indivisbile
Q: The _______ operator takes the results of two queries and returns only rows that appear in both result sets.
A.Union
B.Intersect
C.Difference
D.Projection
Correct Option: BExplanation: The union operator gives the result which is the union of two queries and difference is the one where query which is not a part of second query.
Database Concepts MCQs - Quiz 187