Entity Relationship Diagram Test: Quiz!
(102).jpg "Entity Relationship Diagram Test: Quiz!")
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- 1.ER was developed by Chen in 1980.
- A.
True
- B.
False
- 2.ER was developed by Chen in 1976.
- A.
True
- B.
False
- 3.ER aims to:
- A.
Facilitate database programming
- B.
Facilitate database organization
- C.
Facilitate database design
- 4.The Conceptual data model is the set of concepts that:
- A.
Describe the structure of a database and the associated insert and update transactions
- B.
Describe the structure of a database and the associated retrieval and update transactions
- C.
Describe the structure of a database and the associated retrieval transactions
- 5.An ERs purpose is to support a user's perception of the data and conceal the technical aspects associated with database design.
- A.
True
- B.
False
- 6.A high-level conceptual model is dependent on the DBMS and HW platform used to implement the database.
- A.
True
- B.
False
- 7.The basic concepts of the Entity-Relationship model include:
- A.
Entity types
- B.
File types
- C.
Relationship types
- D.
Atrtributes
- E.
Storage detailes
- 8.Entity type = An object or concept identified by the enterprise as having an ______________ existence.
- 9.A Entity is
- A.
An instance of an Entity type that is uniquely identifiable
- B.
An instance of a DBA type that is uniquely identifiable
- C.
An instance of a type that is uniquely identifiable
- 10.Weak entity type:
- A.
An entity that is not existance-dependent on some other entity type
- B.
An Entity that characterizes a DBMS
- C.
An instance that is existance dependent on some other entity type
- 11.Strong entity type:
- A.
An entity that is not existance-dependent on some other entity type
- B.
An Entity that characterizes a DBMS
- C.
An instance that is existance dependent on some other entity type
- 12.An Attribute is a property of an entity or a relationship type.
- A.
True
- B.
False
- 13.An Attribute:
- A.
a set of values that might be asigned to an atribute
- B.
is a property of an entity or a relationship type
- 14.An Attribute domain:
- A.
a set of values that might be asigned to an atribute
- B.
is a property of an entity or a relationship type
- 15.Simple attribute:
- A.
An attribute that represents a value that is derivable from a related atrribute or set of atributes, not necessarily in the same entity
- B.
An attribute that holds multiple values for a single component
- C.
An attribute that holds a single value for a single entity
- D.
An atribute composed of multiple components each with individual existance
- E.
An atribute composed of a single component with an independent existance
- 16.Composite attribute:
- A.
An attribute that represents a value that is derivable from a related atrribute or set of atributes, not necessarily in the same entity
- B.
An attribute that holds multiple values for a single component
- C.
An attribute that holds a single value for a single entity
- D.
An atribute composed of multiple components each with individual existance
- E.
An atribute composed of a single component with an independent existance
- 17.Single valued attribute:
- A.
An attribute that represents a value that is derivable from a related atrribute or set of atributes, not necessarily in the same entity
- B.
An attribute that holds multiple values for a single component
- C.
An attribute that holds a single value for a single entity
- D.
An atribute composed of multiple components each with individual existance
- E.
An atribute composed of a single component with an independent existance
- 18.Multi- valued attribute:
- A.
An attribute that represents a value that is derivable from a related atrribute or set of atributes, not necessarily in the same entity
- B.
An attribute that holds multiple values for a single component
- C.
An attribute that holds a single value for a single entity
- D.
An atribute composed of multiple components each with individual existance
- E.
An atribute composed of a single component with an independent existance
- 19.Derived attribute
- A.
An attribute that represents a value that is derivable from a related atrribute or set of atributes, not necessarily in the same entity
- B.
An attribute that holds multiple values for a single component
- C.
An attribute that holds a single value for a single entity
- D.
An atribute composed of multiple components each with individual existance
- E.
An atribute composed of a single component with an independent existance
- 20.A Candidate key is an attribute or set of attributes that uniquely identifies individual occurrences of an entity type.
- A.
True
- B.
False
- 21.The Primary key:
- A.
Uniquely identifies each occurance of an entity type
- B.
Is equivalant with a composite key
- C.
Is the candidate key selected to be a primary key
- 22.A Composite key is a candidate key that consists of two or more attributes.
- A.
True
- B.
False
- 23.Degree of a relationship.
- A.
Is always 1
- B.
The number of participating entities in a relationship
- C.
The number of representations in a relationship
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