QUESTIONS AND CORRECT ANSWERS [ALREADY GRADED
A+ NEWEST EDITION 2024
What are the four major DBMS approaches? - (correct answer) - Hierarchical
- Network
- Relational
- Object-oriented
What are four key differences between a RELATION and a FILE? - (correct answer)
- The columns of a relation can be arranged in any order w/o affecting the meaning of
the data. That is not true of a file.
- Similarly, the rows of a relation can be arranged in any order, which is not true of a file.
- Every row/column position, sometimes referred to as a "cell", can have only a single
value, which is not necessarily true in a file.
- No two rows of a relation are identical, which is not necessarily true in a file.
Flat Files - (correct answer) a file having no internal hierarchy
Hashed Files - (correct answer) A file that has been encrypted for security purposes.
Heap File - (correct answer) An unsorted set of records.
Information - (correct answer) The transformation of raw data into useful facts.
Punch Card - (correct answer) A card that is perforated and can hold commands or
data.
Structured Data - (correct answer) Information with a high degree of organization.
Unstructured Data - (correct answer) Information that does not have structure (such
as text)
Binary Relationship - (correct answer) A relationship between two entity types.
Unary Relationship - (correct answer) An associate occurrence of an entity type with
other occurrences of the same entity type.
Cardinality - (correct answer) The maximum number of entities that can be involved
in a particular relationship.
E-R Model
*E-R = Entity - Relationship - (correct answer) Diagram of entities together with their
attributes and the relationship among them.
, Intersection Data - (correct answer) It is data that describes a many-to-many
relationship.
Modality - (correct answer) It is a minimum number of entity occurrences that can be
involved in a relationship.
One-to-one Binary Relationship - (correct answer) It means that a single occurrence
of one entity type can be associated with a single occurrence of the other entity type
and vice versa.
Ternary Relationship - (correct answer) Involves three different entity types.
Unique identifier - (correct answer) It is used to uniquely identify each record in a
database table.
Attribute - (correct answer) A property, characteristic, or fact that we know about an
entity.
"A salesperson works in one office."
What is the name of this relationship? - (correct answer) One-to-one binary
relationship
"A salesperson sells to many customers."
What is the name of this relationship? - (correct answer) One-to-many binary
relationship
"A salesperson is authorized to sell many products, and a product can be sold by many
salespersons."
What is the name of this relationship? - (correct answer) Many-to-many binary
relationship
What is the positioning and meaning for Cardinality and Modality on an E-R model? -
(correct answer) Cardinality is the outer symbol; represents the maximum.
Modality is the inner symbol; represents the minimum.
"A salesperson works in a minimum of one and a maximum of one office, and an office
may be occupied by or assigned to a minimum of zero and a maximum of one
salesperson." - (correct answer)
"A salesperson may have no customers or many customers." - (correct answer)