Chapter 6 Quizlet

A table that has all key attributes defined, has no repeating groups, and all its attributes are dependent on the primary key is said to be in _____.

1NF

From a structural point of view, 2NF is better than _____.

1NF22.

Since a partial dependency can exist only if a table's primary key is composed of several attributes, and if a table in 1NF has a single-attribute primary key, then the table is automatically in _____.

2F

From a structural point of view, 3NF is better than _____.

2NF

Which of the following structures is used in a complex, multilevel, multisource data environment?

2NF

When using a data-modeling checklist to design a new database structure based on the business requirements of the end users, what is the minimum preferred normal form all entities should be in?

3NF

Select one of the following table types which defines a table in 2NF that contains no transitive dependencies?

3nf

A table where all attributes are dependent on the primary key but are independent of each other, and no row contains two or more multivalued facts about an entity is said to be in _____.

4NF

Some very specialized applications may require normalization beyond the _____.

4NF

Which of the following tables contains no rows with two or more multivalued facts about an entity?

4NF

What type of data is stored at their lowest level of granularity.

Atomic

If an attribute cannot be further subdivided, which of the following attributes would it display?

Atomicity

How would Microsoft Access generate a surrogate key?

Autonumber

16. If a table is in the third normal form (3NF) and is also considered to be in Boyce- Codd normal form, what functional dependencies are taken into account as determinants?

Canidate keys

Of the following normal forms, _____ is mostly of theoretical interest.

DKNF

The main goal of normalization is to eliminate

Data abnormalities

In exchange for possible reductions in performance, what unwanted element does normalization reduce?

Data redundancies

__ databases reflect the ever-growing demand for greater scope and depth in the data on which decision support systems increasingly rely.

Data warehouses

The combination of normalization and ER modeling yields a useful _____, whose entities can be translated into appropriate table structures.

ERD

According to the data-modeling checklist, _____ should be nouns that are familiar to business, should be short and meaningful, and should document abbreviations, synonyms, and aliases for each entity.

Entity names

Normalization is a process that is used for changing attributes to entities

False

Which term would you use to refer to the level of detail represented by the values stored in a table's row?

Granularity

An ERD is created through which of the following processes?

Iterative

An unnormalized data structure includes entities that can have relations with many instances of another entity type, for instance, employees that can be assigned to multiple projects. How does this affect adding, updating, and deleting data?

Multiple rows need to be updated

In order for you to yield a useful ERD, you must combine ER modeling with which of the following entities?

Normalization

Which term represents a micro view of the entities within the ERD.

Normalization

If a table in 2NF exhibits a transitive dependency, what does the primary key rely on to functionally determine nonprime attributes?

Other non-prime attributes

Mario wants to choose a dependency which is based on only a part of a composite primary key. Which dependency does Mario choose?

Partial

What type of dependency is shown during normalization, if the conversion to the second normal form involves removing all attributes dependent on only a part of a composite primary key?

Partial dependency

Because a partial dependency can exist only when a table's primary key is composed of several attributes, a table whose _____ key consists of only a single attribute is automatically in 2NF once it is in 1NF.

Primary

What is normalization?

The process that assigns attributes to entites in order to reduce data redundancies

A(n) _____ exists when there are functional dependencies such that Y is functionally dependent on X, Z is functionally dependent on Y, and X is the primary key.

Transitive dependency

All relational tables satisify the 1NF requirement

True

Denormalization produces a lower normal form

True

Dependency diagrams are very helpful in getting a bird-eyes view of all the relationships among a table's attributes

True

In order to meet performance requirements, portions of the database design may need to be occasionally denormalized

True

In the context of partial dependencies, data redundancies occur because every row entry requires the duplication of data

True

Normalization works through a series of stages called normal forms

True

Relational models view data as part of a table or a collection of tables in which all key values must be identified

True

Repeating groups must eliminated by ensuring that each row defines a single entity

True

The objective of normalization is to ensure that each table conforms to the concept of well-formed relations

True

When using a data-modeling checklist to design a data structure, attribute names should:

Use descriptive suffixes

Unnormalized tables yield no simple strategies for creating virtual tables known as _____.

Views

Improving _____ leads to more flexible queries.

atomicity

Which of the following keys in a table would cause you to violate BCNF if used more than once?

canidate

An atomic attribute _____.

cannot be further subdivided

In a(n) _____ diagram, the arrows above the attributes indicate all desirable dependencies.

dependency

When using a system functionality point of view, which attribute values can be calculated when they are needed to write reports or invoices?

derived

Attribute A _____ attribute B if all of the rows in the table that agree in value for attribute A also agree in value for attribute B.

determines

According to the ERD data-modeling checklist, all entities in a relational table represent a single set of distinguishable sets of _____. .

entity instances

Which of the following traits should you balance with design integrity?

flexibility

To eliminate repeating groups and convert a table into the first normal form, what can you change in a table to convert multivalued attributes into a single-valued attribute?

focus

When the related table uses a composite primary key, it becomes difficult to create which key?

foreign

A table is in 4NF if it is in 3NF, and _____.

it has no multivalued dependencies

Which unnormalized attribute in your data structure could make your data management more difficult?

multivalued

If a table is in fourth normal form, it is in third normal form and has no _____.

multivalued dependenceis

Which type of dependency illustrates how one key determines multiple values of two other attributes and those attributes are independent of each other?

multivalued dependency

Raw data in its original state that has data abnormalities such as redundant or multivalued data is

normalized

According to the data-modeling checklist, _____ is a process used to ensure an entity-relationship model minimizes data redundancy to ensure single-place updates.

nromalization

The most likely data type for a surrogate key is _____.

numeric

f a table has multiple candidate keys and one of those candidate keys is a composite key, the table can have _____ based on this composite candidate key even when the primary key chosen is a single attribute.

partia dependicies

A relational table must not contain a(n) _____.

repeating group

0. A _____ derives its name from the fact that a collection of multiple entries of the same type can exist for any single key attribute occurrence.

repeting group

When faced with changing granularity requirements, primary key selections might change which ultimately may require usage of which additional key?

surrogate

Which type of demoralized table holds report data when creating a tabular report in which the columns represent data that are stored in the table as rows?

temporary

When a table contains only one candidate key, _____ are considered to be equivalent.

the 3NF and the BCNF

Granularity refers to _____.

the level of detail represented by the values in a table's row

According to a standard data-modeling checklist, the non-key entities in an entity-relationship (ER) data model must be fully dependent on _____.

the primary key

Normalization purity is often difficult to sustain in the modern database environment due to which of the following?

they contain partial and/or transitive dependencies

Normalization works through a series of stages called normal forms. For most purposes in business database design, _____ stages are as high as you need to go in the normalization process.

three