Database Systems Quiz #1 & #2

entities

Customers, cars, and parts are exampled of:

Recursive relationships

Relationships among entities of the same type are called ___?

Database Instance

Snapshot of the data in the database at a given instant of time is called

disjoint

The ___ rule specifies that an entity can be a member of only one subtype at a time.

partial specialization

The ___ rule specifies that an entity isntance of a supertype is allowed not to belong to any subtype.

snapshot

The a ___ of course data gies the values of all attributes, such as title and department, of all courses at a particular point in time.

DBMS system designers and implementors

They design and implement the DBMS modeuls and interfaces as a software package

Application Programs

To allow users to manipulate the information, the syste has a number of

Primary key values cannot be null according to the entity integrity constraint.

What is TRUE about Entity Integrity Constraints?

Instance

What term is used to refer to a specific record in your music database; for isntance; information stored about a specific album

Phone_number

Which of the following can be a multivalues attribute?

All of the above (DDL, DML, DQL)

Which of the following is Database Language?

total specialization

Which of the following is a completeness constraint?

Suptertype

Which of the following is a generic entity type that has a relationship with one or more subtypes

Network Model

Which of the following is a navigation data model model

Network Maintenance

Which of the following is not a functions of DBA?

Critical Level

Which of the following is not a level of data abstraction

HTML

Which of the following is not involved in DBMS

user

Which of the following isn't a level of abstraction

Enroll

Which would most likely NOT be an entity on an ERM

FALSE

With the traditional file processing approach, each application shares data files, thus enabling much data sharing

Database designers

___ are considered database architects

alter

___ command can be used to modify a column in a table

an attribute or set of attributes that can be the primary key

a "candidate key" is:

All of the above (Collection of data describing one particular enterprise, Collection of programs to access data, Collection of interrelated data)

A Database System is:

disjoint rule

A ___ addresses whether an instance of a supertype may simultaneously be a member of two or more subtypes.

data warehouse

A ___ focuses primarily on storing data used to generate information required to make tactical or strategic decisions

schema

A ___ is used to define overall design of the database

Attribute

A characteristic of an entity

TRUE

A data model is a graphical system used to capture the nature and relationships among data

indivisible

A domain is atomic if elements of the domain are considered to be ___ units.

physical

A level that described how a record is stored

logical

A level that describes data stored in a database and the relationships among the data

Schema

A logical structure of the database

none of the above (does not depend on anything)

A strong entity depends on the following:

Data model

A type of data abstraction that is used to provide a conceptual representation

completeness

A(n) ___ constraint is a type of constraint that addresses whether an insance of a supertype must also be an instance of atleast one subtype.

conceptual

A(n) ___ model is independent of both hardware and software

b and c (Belong to the same entity class & Have the same attributes)

All isntances of a given entity?

derived attribute

An attribute of an entity that is computed is a(n):

One-to-one

An entity in A is associated with at most one entity in B, and an entity in B is associated with at most one entity in A. This is called as

weak

An entity type whose existance depends on another entity type is called a ___ entity

Geographic Information systems (GIS)

Can store and analyze maps, weather data, and satellite images

Both A and B (Data independence & centralized control of data)

DBMS helps achieve

Programs

DBMS is a set of ___ to access the data

End Users

DBMS manages the interaction between ___ and database.

Create information table in the Database

Data Manipulation Language (DML) is not to

All the above (Retrieval of information stored in database, Insertion of new information into the database, Deletion of information from the database)

Data Manipulation Language enables users to

redundancy

Data ___ exists when the dame data are stored unnecessarily at different places

Both B & C (Programs are not dependent on the physical attributes of data & Programs are not dependent on th elogical attributes of data)

Data independence means

File processing system

Data redundancy and Data inconsistency is one of the major drawbacks of

Call the DBMS to access stored data

Database processing programs

cascade

Deletion of an employee from table also delete that employee from another table. This kind of delete is called ___

assertion

Domain constraints, functional dependency and referencetial integrity are special forms of ___.

FALSE

ERM is an acronym for Enterprise Reliability Model

All of the above (Data is separated and isolated, Data is often duplciated, Application programs are dependent on file format)

File processing systems have important limitations

only one supertype

In a supertype/subtype hierarchy, each subtype has:

supertypes

In a supertype/subtype hierarchy, subtypes that are lower in the hierarchy inherit attributes from not only their immediate supertype but from all ___ in the hierarchy.

FALSE

In an entity called STUDENT, you might find attributes of PROFESSOR-ID, Last-Name, First-Name, and CLASSROOM

A multivalues attribute of an entity set

In which of the following, a separate relation is created consisting of that attribute and the primary key of the entity set.

Stringent real-time requirements

It is better to use fiels than a DBMS when there are

Delete from R2

Let R1(A, B, C, D) and R2(P, Q, R, S) be two relations in which A is the foreign key of R1 that refers to the primary key of R2. Which of the following operations causes the referential integrity constraint violation

Database Schema

Logical design of database is called

Both the statems are true

Statement 1: A tuple is a row in a relation. Statement 2: Existance of multiple foreign keys in a same relation is possible.

there are attributes that apply to some but not all instances of an entity type

Subtypes should be used when:

any

The Tuples of the relations can be of ___ order.

view

The ___ level helps applciation programs hide the details of data types

total specialization

The ___ rule specified that each entity isntance of the supertype must be a member of some subtype in the relationship.

tree structure

The hierarchical database model is based on a

predicate-defined subclass

The kind of subclass on which the entity become part of subclass by putting some condition on attribute value sis classified as

entity-relationship model

The logical representation of an organization's data is called a(n):

one

The number of entity types that participate in a Unary relationship is:

specialization

The process of defining one or more subtypes of a supertype and forming relationships is called:

All of the above (It is an integrated collection of logically related records, It consolidated separate files into a common pool of data records, Data stored in a database is independent of the application programs using it)

The property / properties of a database is / are:

Constraint

The restrictions placed on the data

subset of the union of all its superclasses

The set of entities in a union (category) class is

No proper subset is also a super key

The subset of a super key is a candidate key under what condition?

No proper subset is a super key

The subset of super key is a candidate key under what condition?

Relationship, attribute, entity

The three major parts of an ERM diagram are:

Instance

he actual content in the database at a particular point