Which aggregate function calculates the average value of a numeric column?
Anonymous Quiz
11%
SUM
67%
AVG
11%
MIN
11%
COUNT
Which of the following commands is considered DML (Data Manipulation Language)?
Anonymous Quiz
0%
ALTER TABLE
57%
DROP TABLE
14%
CREATE TABLE
29%
INSERT INTO
What is used to assign a temporary name to a table in a query (e.g., in self-joins)?
Anonymous Quiz
22%
Schema
22%
Subquery
0%
View
56%
Alias
A statement that is used to define the structure of a relation is called a:
Anonymous Quiz
33%
DML command
44%
DDL command
22%
Procedural command
0%
DCL command
When mapping a Strong Entity Type, the resulting relations Primary Key is:
Anonymous Quiz
40%
The Partial Key of the entity
30%
The Foreign Key to its owner
30%
The Primary Key of the entity type
0%
A new surrogate key
When mapping a Weak Entity Type, its resulting relations Primary Key is formed by combining its Partial Key with:
Anonymous Quiz
30%
A new surrogate key
0%
The Partial Key alone
20%
The Foreign Key of a Superclass
50%
The Primary Key of the Owner Entity
For a 1:N Relationship (R from E1 to E2), the Foreign Key is placed in the relation corresponding to:
Anonymous Quiz
22%
The N-side entity (E2)
44%
A separate relation (R)
33%
Both E1 and E2
0%
The 1-side entity (E1)
For an M:N Relationship, the required mapping step is to:
Anonymous Quiz
11%
Place the FK in the N-side relation
67%
Create a new relation for the relationship type
11%
Place the FK in the M-side relation
11%
Combine the attributes into a single relation
When mapping a Composite Attribute, the common approach is to:
Anonymous Quiz
10%
Treat it as a Multivalued attribute
60%
Include only its simple component attributes in the relation
10%
Discard the attribute
20%
Create a separate relation for the attribute
A Multivalued Attribute is mapped by:
Anonymous Quiz
0%
Discarding it
75%
Creating a new relation with the entitys PK and the attribute
0%
Treating it as a Composite Attribute
25%
Including its values in the main entity relation
In a 1:1 Relationship, the Foreign Key should ideally be placed in the relation corresponding to the entity with the:
Anonymous Quiz
20%
Maximum number of attributes
30%
Total participation constraint
20%
Partial participation constraint
30%
Minimum number of attributes
The general rule for mapping an N-ary Relationship (N > 2) is to:
Anonymous Quiz
11%
Map it into two 1:N relations
22%
Map it into N binary relations
67%
Create a new relation for the relationship type
0%
Combine the relationship attributes into one entity relation
❤1
One option for mapping a Total, Disjoint Specialization is to create a single relation for the Superclass and Subclasses, adding a Type Attribute and:
Anonymous Quiz
33%
Foreign Keys to all Subclasses
67%
NULL values for the specific attributes of other subclasses
0%
Only the key attribute
0%
Multiple Foreign Keys to itself
The Primary Key of the new relation created from a M:N Relationship is typically the combination of:
Anonymous Quiz
0%
A new surrogate key
33%
The primary key of one participating entity
0%
Its own attributes only
67%
The Foreign Keys of both participating entities
In the mapping option where only relations for subclasses are created (Mapping Option 2 for Specialization), the Primary Key of the Subclass relation is:
Anonymous Quiz
10%
The Primary Key of the Superclass
30%
A newly generated key
40%
The Partial Key of the subclass
20%
The combination of all its attributes
The mapping of a Category (Union Type) involves creating a relation for the Category, including a surrogate key, the Categorys attributes, and:
Anonymous Quiz
10%
No Foreign Keys
50%
Foreign Keys from all participating entities
30%
A Foreign Key to only one participating entity
10%
Only the Primary Key of the Superclass
If a Specialization is Overlapping, which mapping option is generally preferred to handle multiple inheritance effectively?
Anonymous Quiz
36%
Option 2 (Subclasses Only)
55%
Option 3 (Superclass and Subclasses)
9%
Option 4 (Combination of relations)
0%
Option 1 (Single Relation)
When mapping a Derived Attribute, the attribute is usually:
Anonymous Quiz
30%
Ignored in the mapping process
20%
Treated as a Multi-valued attribute
10%
Mapped as a separate relation
40%
Included in the relation and marked as NOT NULL
To enforce the Total Participation constraint of E2 in a 1:N relationship R, the Foreign Key placed in the relation corresponding to E2 must be specified as:
Anonymous Quiz
11%
UNIQUE
56%
NOT NULL
11%
DEFAULT value
22%
CHECK constraint
When mapping a Total Specialization (Option 3: Superclass and Subclasses), the primary key of the Subclass relation is also a:
Anonymous Quiz
0%
Alternate Key
40%
Foreign Key
40%
Secondary Key
20%
Candidate Key