test 2

Associative entity in ER diagram:

3 relations, 1 with 2 primary keys pointing to both of the other primary keys in each relation

Which of the following is not true? a. an entity type name does not have to be unique b. a single occurrence of an entity is called an entity instance c. a business rule should be internally consistent d. the e-r model is used to construct a conceptual model e. when choosing an identifier, choose one that will not change its value often

a. an entity type name does not have to be unique

Database development begins with _______________, which establishes the scope and general contents of organizational databases. a. enterprise data modeling b. database design c. cross-functional analysis d. departmental data modeling e. interface design

a. enterprise data modeling

Which of the following is an entity that exists independently of other entity types? a. strong b. weak c. associative d. codependent e. variant

a. strong

_________ concentrate on determining the requirements and design for the database component of the information system. a. business analyst b. database analyst c. system analyst d. programmers e. users

b. database analysts

The number of entity types that participate in a relationship is called the: a. number b. degree c. cardinality d. identifying characteristic e. counter

b. degree

The number of entity types that participate in a Unary relationship is: a. uncertain b. zero c. one d. two e. three

c. one

How many relations in total are resulted from mapping an ER diagram which contains two entities and a many-to-many relationship a. 0 b. 1 c. 2 d. 3 e. 4

d. 3 many-to-many: add relation w/ two primary keys

The traditional methodology used to develop, maintain and replace information systems is called the: a. Database Implementation b. Unified Model c. Enterprise Resource Model d. Systems Development Life Cycle e. Physical Schema

d. Systems Development Life Cycle

The property by which subtype entities possess the values of all attributes of a supertype is called: a. hierarchy reception b. generalization c. specialization d. attribute inheritance e. class management

d. attribute inheritance

A rule that CANNOT be violated by database users is called a(n): a. password b. application c. program d. constraint e. view

d. constraint

Which of the following is NOT an advantage of database systems? a. program-data independence b. better data quality c. reduced program maintenance d. eliminated data redundancy e. improved data consistency

d. eliminated data redundancy

A dependency where one or more nonkey attributes are dependent on another nonkey attribute is called a _______ dependency. a. merges relation b. key-based c. partial d. transitive e. cross key

d. transitive

Which of the following are properties of relations? a. no two rows in a relation are identical b. each attribute has the same name c. there are multivalued attributes in a relation d. all columns are numeric e. simple, surrogate keys should not be used in place of composite, primary keys

a. no two rows in a relation are identical

Which of the following has a relationship with one or more subtypes? a. supertype b. megatype c. subgroup d. class e. table

a. supertype

A candidate key must satisfy all of the following conditions EXCEPT: a. the key must indicate the row's position in the table b. the key must be nonredundant c. each nonkey attribute is functionally dependent upon it d. the key must uniquely identify the row e. a candidate key is always a determinant

a. the key must indicate the row's position in the table

Subtypes should be used when: a. there are attributes that apply to some but not all instances of an entity type b. supertypes relate to objects outside of business c. the instances of a subtype do not participate in a relationship that is unique to that subtype d. a recursive relationship is needed e. modeling data for every organization

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

The _________ states that no primary key attribute may be null a. range domain b. entity integrity c. referential integrity d. completeness e. partial specialization

b. entity integrity

A constraint where the value of one attribute determines the value of another attribute is called a(n): a. functional relation b. functional dependency c. domain constraint d. functional relation constraint e. composite attribute

b. functional dependency

_________ anomalies can be caused by editing data in tables. a. insertion b. modification c. deletion d. creation e. selection

b. modification

Customers, cars, and parts are examples of: a. business rules b. relationships c. entities d. attributes e. cardinalities

c. entities

A(n) __________ contains important metadata for managing the database. a. application b. DBMS c. repository d. user interface e. PC

c. repository

In the relational data model, data is represented in the form of: a. trees b. notes c. tables d. spreadsheets e. links

c. tables

In the SQL language, which of the following statement is NOT used to make table definitions? a. CREATE TABLE b. PRIMARY KEY c. FOREIGN KEY REFERENCES d. NOT NULL e. SELECT

e. SELECT

A person's name, birthday, and social security number are all examples of: a. relationships b. entities c. identifiers d. descriptors e. attributes

e. attributes

All of the following are the main goals of normalization EXCEPT: a. minimize data redundancy b. simplify the enforcement of referential integrity c. make it easier to maintain data d. provide a basis for future growth e. consume more storage space

e. consume more storage space

The logical representation of an organization's data is called a(n): a. database model b. database development cycle c. relationship systems design d. database entity diagram e. entity-relationship model

e. entity-relationship model

A database is an organized collection of ________ related data: a. badly b. loosely c. remotely d. physically e. logically

e. logically

An attribute that can be broken down into smaller parts is called a(n) ______ attribute. a. associative b. simple c. complex d. composite e. multivalued

e. multivalued

The _________ rule specifies that an entity can be a member of only one subtype at a time a. exclusion b. disjoint c. removal d. inclusion e. completeness

b. disjoint ex: you can't be a outpatient and a resident patient overlap rule:an entity can be a member of both subtype groups

An attribute that may have more than one meaning is called a(n): a. inter-table primary key b. enterprise key c. global primary key d. global foreign key e. objectID

b. enterprise key

The ____________ rule specifies that each entity instance of the supertype must be a member of some subtype in the relationship a. disjoint b. convergence c. partial specialization d. total specialization e. semi-specialization

d. total specialization ex: you MUST be an outpatient or a resident patient to be a patient partial specialization: each entity instance of the supertype is allowed not to be a member of some subtype in the relationship

How many relations in total are resulted from mapping a ternary relationship? a. 0 b. 1 c. 2 d. 3 e. 4

e. 4