Database

Database

Object-Oriented Database has 30 Questions

ODL supports the abstract keyword for classes and operations.

True
False
ODL supports which of the following types of association relationships?

Unary
Unary and Binary
Unary and Binary and Ternary
Unary and Binary and Ternary and higher
The ODMG Object Model requires that a relationship be specified in both directions.

True
False
     An extent is which of the following?

A keyword that indicates that the subclass inherits from a superclass
A keyword that indicates that the superclass inherits from a subclass
The set of all instances of a class within a database
Only one instance of a class within a database
Before specifying a key for a class, you must specify its extent.

True
False
Identify the class name for the following code: ABC123 course();

ABC123
course
course()
All of the above.
The Object Model supports different literal types, but does not support atomic literals, collection literals, and structured literals.

True
False
Using ODL, you can define which of the following?

Attribute
Structure
Operation
All of the above.
The ODMG Object Model supports only unary and binary relationships.

True
False
The keyword "inverse" is used in which of the following?

Class
Attribute
Relationship
All of the above.
Literals do not have identifiers, and, therefore, cannot be individually referenced like objects.

True
False
The object definition language (ODL) is which of the following?

Used to develop logical schemas
A data definition language for OODB
A method to implement a logical schema
All of the above.
A collection of literals or object types is called a bag.

True
False
An atomic literal is which of the following?

Strings
Boolean
Long
All of the above.
An attribute's value is either a literal or an object identifier.

True
False
Which of the following is true concerning an ODBMS?

They have the ability to store complex data types on the Web.
They are overtaking RDBMS for all applications.
They are most useful for traditional, two-dimensional database table applications.
All of the above.
The reserved word enum is used for which of the following?

To define a range for an attribute.
To define a range for a class.
To define a range for a relationship.
All of the above.
Database objects are almost always transient.

True
False
Which of the following is an unordered collection of elements that may contain duplicates?

Set
Bag
List
Dictionary
An attribute's value is always literal.

True
False
Which of the following is true concerning the following statement: class Manager extends Employee

Manager is a concrete class and a superclass.
Manager is a concrete class and a subclass.
Manager is an abstract class and a superclass.
Manager is an abstract class and a subclass.
Specifying a key ensures that no two objects belonging to a class have the same value for the key attribute(s).

True
False
Which of the following is an ordered collection of elements of the same type?

Set
Bag
List
Dictionary
If you know all the possible values that an attribute can have, you can enumerate those values in ODL.

True
False
A relationship should be specified how in the ODL?

One direction starting with the first class
One direction starting with the second class
Neither direction.
Both directions.
You may specify an object identifier with only one unique tag name.

True
False
Using OQL, you may do which of the following?

Return an entire collection of elements including duplicates.
Return a collection of elements without duplicates.
Return a specific subset of elements using a given criteria.
All of the above.
In ODL, you specify an operation using parentheses after its name.

True
False
The Object Query Language is which of the following"?

Similar to SQL and uses a select-from-where structure
Similar to SQL and uses a select-where structure
Similar to SQL and uses a from-where structure
Not similar to SQL
An ordered collection of elements of the same type are called sets.

True
False