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
The Foreign Key in the relation corresponding to the Weak Entity must also be specified as:
Anonymous Quiz
27%
CHECK constraint
36%
NOT NULL
27%
UNIQUE
9%
DEFAULT value
When mapping a 1:1 Relationship, if both sides have Partial Participation, a separate relation might be the optimal choice to minimize:
Anonymous Quiz
0%
Update anomalies
38%
NULL values
25%
Key constraint violations
38%
Referential integrity violations
Mapping a generalization lattice (multiple inheritance) is most often handled using:
Anonymous Quiz
0%
Option 4
50%
Option 2 or 3
0%
Option 5
50%
Option 1 (Single Relation)
The key for a separate relation created from a Multivalued Attribute is the combination of the entitys Primary Key and the:
Anonymous Quiz
20%
Foreign Key
60%
Primary Key of the Superclass
10%
New Surrogate Key
10%
Attribute value itself
Section 8: أسئلة من الاختبار النصفي
#أساسيات_قواعد_البيانات
#databases_fundamentals
#علم_البيانات الدفـعـ(1)ــة
Loading the initial database contents on a secondary storage medium is a phase of:
Anonymous Quiz
9%
Defining a database
36%
Manipulating a database
9%
Sharing a database
45%
Constructing a database
A special null value is used to represent values that are:
Anonymous Quiz
0%
Equal to zero (0)
83%
Not applicable or unknown
8%
Always invalid input
8%
Temporarily deleted
Which of the following is NOT one of the three main types of Explicit schema-based constraints in the Relational Model?
Anonymous Quiz
36%
Entity integrity constraints
18%
Key constraints
36%
Domain constraints
9%
Referential integrity
All the following are types of recent database applications EXCEPT:
Anonymous Quiz
0%
Data Warehouse
0%
Mobile database
30%
Multimedia database
70%
Numeric and textual database
Which of the following describes properties used to describe an entity?
Anonymous Quiz
33%
Relationship
8%
Entity
58%
Attributes
0%
Tuple
Which term is the informal name for a Tuple in the Relational Model?
Anonymous Quiz
8%
Relation
33%
Key
33%
Row
25%
Attribute