Question 1

A missing value is called a(n)________.

Accepted Answer

A missing value is typically referred to as a "null value" in database terminology.

Question 2

When accessing table structure,how do you determine how many rows are in a table?

Accepted Answer

The answer of When accessing table structure,how do you determine...

Question 3

The problem of misspelled data entries is really the same as ________.

Accepted Answer

Misspelled data entries result in inconsistent values, as they do not match the correct spelling of the intended entry.

Question 4

Reviewing the work done on a table that was created using existing data from multiple sources,you are likely to find that some data values that were provided were never entered into the table.This is an example of ________.

Accepted Answer

The missing values problem refers to the issue of data values that are not present or were not entered into the table. This is different from the multivalued, multicolumn problem which involves data that contains multiple values that should be separated into different columns, and the inconsistent values problem which involves data that is conflicting or does not follow a standard format. The general-purpose remarks column problem involves the overuse of a single column for multiple types of data, making it difficult to analyze or sort the data effectively.

Question 5

The SQL keyword IS NULL can be used to ________.

Accepted Answer

The SQL keyword IS NULL is used to check for NULL values in a column, allowing you to count the number of null values when used in conjunction with a COUNT function.

Question 6

When a table is created using existing data from multiple sources,you are likely to find that some data values have never been provided.This is an example of ________.

Accepted Answer

The missing values problem refers to the situation where data values have not been provided for some records or observations in a dataset. This can occur when creating a table using existing data from multiple sources, as not all sources may have provided data for all records. The multivalued, multicolumn problem refers to a situation where a table has columns that can contain multiple values, leading to redundancy and inconsistency. The inconsistent values problem refers to a situation where there are discrepancies or conflicts in the data values provided. The general-purpose remarks column problem refers to the use of a single column to store various types of information, leading to ambiguity and difficulty in querying the data.

Question 7

To check for null values in a column in a table,use the SQL phrase ________.

Accepted Answer

"IS NULL" is the SQL phrase used to check for null values in a column. Option A "IS" would be used to check for a specific value while option B "IS NOT" would be used to check for values that are not null. Options D and E are incomplete and cannot be used to check for null values.

Question 8

What are null values,and why are they a problem?

Accepted Answer

The answer of What are null values,and why are they...

Question 9

When a table is created using existing data from multiple sources,you are likely to find that some data values have never been provided.This is an example of ________.

Accepted Answer

The missing values problem refers to the situation where some data values have not been provided in the source data. This can happen when creating a table from multiple sources, as not all sources may have the same level of completeness in their data. The other options listed (multivalued, multicolumn problem; inconsistent values problem; and general-purpose remarks column problem) are all potential data modeling issues, but they do not specifically pertain to missing values.

Question 10

What is the multivalue,multicolumn problem,and why is it a problem?

Accepted Answer

The answer of What is the multivalue,multicolumn problem,and why is...

Question 11

What are general-purpose remarks columns,and why are they a problem?

Accepted Answer

The answer of What are general-purpose remarks columns,and why are...

Question 12

When accessing table structure,how do you determine the number and types of columns in a table?

Accepted Answer

The answer of When accessing table structure,how do you determine...

Question 13

What are inconsistent values,and why are they a problem?

Accepted Answer

The answer of What are inconsistent values,and why are they...

Question 14

Reviewing the work done on a table that was created using existing data from multiple sources,you find that a column name Remarks has been included,and it is populated with inconsistent and verbose verbal data.This is an example of ________.

Accepted Answer

The presence of an inconsistent and verbose Remarks column is a common problem and is known as the general-purpose remarks column problem, where data that does not fit into any other column is dumped into a catch-all column. This can lead to difficulties in data analysis and processing as inconsistent or irrelevant data can be included in this column, making it difficult to derive meaningful insights from the data. It is generally recommended to avoid such catch-all columns and instead include separate columns for relevant data.

Question 15

You are creating a PRODUCT table using existing data from multiple sources.Examining the data,you find that you have "large red hat","large hat,red","red hat large" and "hat,large,red." This is an example of ________.

Accepted Answer

The inconsistent values problem refers to the issue of having varied formats or values for the same data element, which is evident in the different formats of "large red hat" in the given example. The other options do not apply to this scenario - the multivalue, multicolumn problem would occur if there were multiple values or attributes for a single field, the missing values problem would occur if there were null values in the data, and the general-purpose remarks column problem refers to the practice of creating a catch-all column for any type of data, which is not relevant in this situation.

Question 16

What are the advantages and disadvantages of normalization?

Accepted Answer

The answer of What are the advantages and disadvantages of...

Question 17

Explain denormalization,and why it may be appropriate to denormalize a set of tables.

Accepted Answer

The answer of Explain denormalization,and why it may be appropriate...

Question 18

A null value can indicate which of the following conditions?

Accepted Answer

A null value can indicate that the value is inappropriate, unknown, or not entered, covering all scenarios in A, B, and C.

Question 19

When accessing table structure,and determining the number and types of columns in a table,how can you control how many rows are returned?

Accepted Answer

The answer of When accessing table structure,and determining the number...

Question 20

Describe the steps in assessing table structure when you are given a set of tables and asked to construct a new database to store the existing data.

Accepted Answer

The answer of Describe the steps in assessing table structure...

Quiz 4: Database Design Using Normalization

A missing value is called a(n) ________.

When accessing table structure,how do you determine how many rows are in a table?

The problem of misspelled data entries is really the same as ________.

Reviewing the work done on a table that was created using existing data from multiple sources,you are likely to find that some data values that were provided were never entered into the table.This is an example of ________.

The SQL keyword IS NULL can be used to ________.

When a table is created using existing data from multiple sources,you are likely to find that some data values have never been provided.This is an example of ________.

To check for null values in a column in a table,use the SQL phrase ________.

What are null values,and why are they a problem?

When a table is created using existing data from multiple sources,you are likely to find that some data values have never been provided.This is an example of ________.

What is the multivalue,multicolumn problem,and why is it a problem?

What are general-purpose remarks columns,and why are they a problem?

When accessing table structure,how do you determine the number and types of columns in a table?

What are inconsistent values,and why are they a problem?

Reviewing the work done on a table that was created using existing data from multiple sources,you find that a column name Remarks has been included,and it is populated with inconsistent and verbose verbal data.This is an example of ________.

You are creating a PRODUCT table using existing data from multiple sources.Examining the data,you find that you have "large red hat","large hat,red","red hat large" and "hat,large,red." This is an example of ________.

What are the advantages and disadvantages of normalization?

Explain denormalization,and why it may be appropriate to denormalize a set of tables.

A null value can indicate which of the following conditions?

When accessing table structure,and determining the number and types of columns in a table,how can you control how many rows are returned?

Describe the steps in assessing table structure when you are given a set of tables and asked to construct a new database to store the existing data.