Database Analysis Chapters 3-4

The relational data model consists of which components? Data structure Data manipulation Data integrity All of these

All of these

Which of the following anomalies result from a transitive dependency? Insertion Modification Deletion All of these

All of these

Which of the following are anomalies that can be caused by redundancies in tables? Insertion Deletion Modification All of these

All of these

An understanding of how to merge relations is important because: there may be a need to merge relations on projects with subteams. different views may need to be integrated. new data requirements may produce new relations to be merged. All of these.

All of these.

Physical database design decisions must be made carefully because of impacts on: data accessibility. response times. security. All of these.

All of these.

Which of the following are properties of relations? Each attribute has a unique name. No two rows in a relation are identical. There are no multivalued attributes in a relation. All of these.

All of these.

________ is a component of the relational data model included to specify business rules to maintain the integrity of data when they are manipulated. Business rule constraint Data integrity Business integrity Data structure

Data integrity

Given the following entities, which of the choices below would be the most complicated? Automobile: VIN, EngineSize, NumberOfDoors, NumberOfPassengers, FuelType, Transmission SUV: VIN, EngineSize, NumberOfPassengers, NoWheelDrive, FuelType, Transmission Truck: VIN, EngineSize, NoWheelDrive, FuelType, Transmission, Payload Define one vehicle entity type to hold all entities. Define a separate entity type for each entity. Define a supertype called vehicle and make each of the entities subtypes. Keep only the Truck entity type.

Define one vehicle entity type to hold all entities.

An attribute of the supertype that determines the target subtype(s) is called the: determinant. subtype decision. disjoint indicator. None of these.

N

Which of the following is NOT a reason to create an instance of a relational schema with sample data? Sample data can be used to improve user communications. Sample data can be used for prototype generation. Sample data can reverse database implementation errors. Sample data provide a convenient way to check the accuracy of your design.

Sample data can reverse database implementation errors.

A relation that contains no multivalued attributes and has nonkey attributes solely dependent on the primary key but contains transitive dependencies is in which normal form? First Second Third Fourth

Second

Which of the following is a generic entity type that has a relationship with one or more subtypes? Megatype Supertype Subgroup Class

Supertype

Which of the following is a completeness constraint? Total specialization Partial generalization Total recall Partial hybridization

Total specialization

An alternative name for an attribute is a(n): synonym. alias. alternate attribute. related characteristic.

alias.

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

attribute inheritance.

A(n) ________ constraint is a type of constraint that addresses whether an instance of a supertype must also be an instance of at least one subtype. disjoint overlap completeness weak

completeness

A primary key that consists of more than one attribute is called a: foreign key. composite key. multivalued key. cardinal key.

composite key.

In the SQL language, the ________ statement is used to make table definitions. create session create table create index select

create table

When a regular entity type contains a multivalued attribute, one must: create a single relation with multiple lines for each instance of the multivalued attribute. create two new relations, one containing the multivalued attribute. create two new relations, both containing the multivalued attribute. None of these.

create two new relations, one containing the multivalued attribute.

A good method for identifying inconsistencies and finding hidden meaning in the customized purchased data model is: data analysis. data volume usage analysis. user interviews. data profiling.

data profiling.

A nonkey attribute is also called a(n): column. unimportant datum. descriptor. address.

descriptor.

The attribute on the left-hand side of the arrow in a functional dependency is the: candidate key. determinant. foreign key. primary key.

determinant.

The most important challenge of customizing a purchased data model is: getting user buy-in. determining the business rules that will be established through the data model. implementation. user training.

determining the business rules that will be established through the data model.

The ________ rule specifies that an entity can be a member of only one subtype at a time. exclusion disjoint removal inclusion

disjoint

A ________ addresses whether an instance of a supertype may simultaneously be a member of two or more subtypes. disjointedness constraint disjoint rule partial specialization total specialization

disjointedness constraint

When identifying with the parts of the packaged data model that apply to your organization, you should first start with: entities. attributes. primary keys. relationships.

entities.

The ________ states that no primary key attribute may be null. referential integrity constraint entity integrity rule partial specialization rule range domain rule

entity integrity rule

When all multivalued attributes have been removed from a relation, it is said to be in: first normal form. second normal form. Boyce-Codd normal form. third normal form.

first normal form.

The process of defining a more general entity type from a set of more specialized entity types is called: generalization. specialization. normalization. None of these.

generalization.

An attribute that may have more than one meaning is called a(n): homonym. alias. double defined attribute. synonym.

homonym.

A domain definition consists of the following components EXCEPT: domain name. data type. integrity constraints. size.

integrity constraints.

The third step in the data modeling process with a packaged data model is: rename identified data elements. rename relationships. map data to be used from package to data in current databases. interview users.

map data to be used from package to data in current databases.

All of the following are the main goals of normalization EXCEPT: minimize data redundancy. simplify the enforcement of referential integrity. maximize storage space. make it easier to maintain data.

maximize storage space.

In a supertype/subtype hierarchy, each subtype has: only one supertype. many supertypes. at most two supertypes. at least one subtype.

only one supertype.

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

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

Subtypes should be used when: there are attributes that apply to some but not all instances of an entity type. supertypes relate to objects outside the business. the instances of a subtype do not participate in a relationship that is unique to that subtype. None of these.

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

The ________ rule specifies that each entity instance of the supertype must be a member of some subtype in the relationship. semi-specialization total specialization partial specialization total convergence

total specialization

A functional dependency between two or more nonkey attributes is called a: partial functional dependency. partial nonkey dependency. transitive dependency. partial transitive dependency.

transitive dependency.

A generic or template data model that can be reused as a starting point for a data modeling project is called a(n): packaged data model. universal data model. enterprise data model. None of these.

universal data model.

All of the following are steps to using a packaged data model EXCEPT: identify the parts of the data model that apply to your data modeling situation. utilize all business rules that come with the packaged data model. rename the identified data elements. map data to be used in packages with existing data in the current databases.

utilize all business rules that come with the packaged data model.

An attribute in a relation of a database that serves as the primary key of another relation in the same database is called a: link attribute. link key. foreign key. foreign attribute.

foreign key.

A constraint between two attributes is called a(n): functional relation. attribute dependency. functional dependency. functional relation constraint.

functional dependency.

All of the following are advantages of packaged data models EXCEPT: packaged data models can be built using proven components evolved from cumulative experiences. projects take less time and cost less. the data model is easier to evolve. more one-to-one relationships give the data model more flexibility.

more one-to-one relationships give the data model more flexibility.

The entity integrity rule states that: no primary key attribute can be null. referential integrity must be maintained across all entities. each entity must have a primary key. a primary key must have only one attribute.

no primary key attribute can be null.

The ________ rule states that an entity instance can simultaneously be a member of two (or more) subtypes. disjoint overlap partial specialization total specialization

overlap

The subtype discriminator is a composite attribute when there is a(n): overlap rule. disjoint rule. partial specialization. full specialization.

overlap rule.

A functional dependency in which one or more nonkey attributes are functionally dependent on part, but not all, of the primary key is called a ________ dependency. partial key-based partial functional cross key merged relation

partial functional

The ________ rule specifies that an entity instance of a supertype is allowed not to belong to any subtype. semi-specialization total specialization partial specialization disjointedness

partial specialization

A form of database specification that indicates all the parameters for data storage that are then input to database implementation is: logical. physical. schematic. conceptual.

physical.

An attribute (or attributes) that uniquely identifies each row in a relation is called a: column. foreign field. primary key. duplicate key.

primary key.

A rule that states that each foreign key value must match a primary key value in the other relation is called the: referential integrity constraint. key match rule. entity key group rule. foreign/primary match rule.

referential integrity constraint.

A two-dimensional table of data is called a: group. set. declaration. relation.

relation.

Packaged data models: are ready to use right out of the box. require customization. allow partial specialization. cannot be used for most applications.

require customization.

The process of defining one or more subtypes of a supertype and forming relationships is called: specialization. generalization. creating discord. selecting classes.

specialization.

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. subtypes supertypes constraints dimensions

supertypes

Two or more attributes having different names but the same meaning are called: homonyms. aliases. synonyms. alternate attributes.

synonyms.

A relation that contains minimal redundancy and allows easy use is considered to be: clean. simple. complex. well-structured.

well-structured.

Understanding the steps involved in transforming EER diagrams into relations is important because: you must be able to check the output of a CASE tool. there are rarely legitimate alternatives from which to choose. CASE tools can model any situation. None of these.

you must be able to check the output of a CASE tool.