Chapter 6: SQL For Data Analysis

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

1NF, 2NF, and 3NF are _____.

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

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.

Normalization is a very important database design ingredient, and the highest level is always the most desirable.

Normalization produces a lower normal form.

Normalization works through a series of stages called normal forms.

_____ is a process to help reduce the likelihood of data anomalies.

Any attribute that is at least part of a key is known as a _____.

An attribute that is part of a key is known as a(n) _____ attribute.

The problem with transitive dependencies is that they still yield data _____.

A table that displays data redundancies yields _____.

All relational tables satisfy the _____ requirements.

When designing a database, you should _____.

Data redundancy produces _____ .

From a system functionality point of view, _____ attribute values can be calculated when they are needed to write reports or invoices.

Reporting anomalies in a table can cause a multitude of problems for managers and can be fixed through application programming.

Data redundancy produces data anomalies.

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

When designing a new database structure based on the business requirements of the end users, the database designer will construct a data model using a technique such as _____.

BCNF can be violated only if the table contains more than one _____ key.

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

If you have three different transitive dependencies, _____ different determinant(s) exist.

Dependencies based on only a part of a composite primary key are known as _____ dependencies.

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.

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

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.

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.

Before converting a table into 3NF, it is imperative that the table already be in _____.

A table that is in 2NF and contains no transitive dependencies is said to be in _____.

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

Any attribute whose value determines other values within a row is known as a _____.

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.

A table is in BCNF if every determinant in the table is a candidate key.

If 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.

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

A dependency based on only a part of a composite primary key is known as a partial dependency.

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

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

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

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

Dependencies that are based on only a part of a composite primary key are called transitive dependencies.

All relational tables satisfy the 1NF requirements.

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

Since a partial dependency can exist only if a table's primary key is composed of several attributes, if a table in 1NF has a single-attribute primary key, then the table is automatically in 2NF.

It is possible for a table in 2NF to exhibit transitive dependency, where the primary key may rely on one or more nonprime attributes to functionally determine other nonprime attributes.

A determinant is any attribute whose value determines other values within a column.

A dependency of one nonprime attribute on another nonprime attribute is a partial dependency.

A dependency based on only a part of a composite primary key is called a _____.

Dependencies can be identified with the help of a dependency _____.

The _____ is central to a discussion of normalization.

In the _____, no row may contain two or more multivalued facts about an entity.

Some very specialized applications may require normalization beyond the _____.

For most business transactional databases, we should normalize relations into _____.

Most designers consider the BCNF as a special case of the _____.

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 _____.

A table that is in 1NF and includes no partial dependencies is said to be in _____.

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

An atomic attribute _____ .

An attribute that cannot be further subdivided is said to display _____.

Improving _____ leads to more flexible queries.

_____ refers to the level of detail represented by the values stored in a table's row.

Granularity refers to _____.

In a real-world environment, changing granularity requirements might dictate changes in primary key selection, and those changes might ultimately require the use of _____ keys.