Database Management Quiz: Lesson 4
You have been given two tables, CUSTOMER and SALE. You want to check the referential integrity constraint: What is shown in the results of this query? SALE.CustomerNumber must exist in CUSTOMER.CustomerNumber You run the following SQL query: SELECT CustomerNumber FROM SALE WHERE CustomerNumber NOT IN (SELECT CustomerNumber FROM CUSTOMER); All values of CustomerNumber where SALE.CustomerNumber = CUSTOMER.CustomerNumber. All values of CustomerNumber that match the constraint. All values of Customer number that are in CUSTOMER but not in SALE. All values of CustomerNumber that violate the constraint.
All values of CustomerNumber that violate the constraint.
Anomalies caused by functional dependencies can be eliminated by putting tables into ________. 1NF 2NF 3NF BCNF
BCNF
The first step in assessing table structure includes ________. counting rows examining columns examining data values Both counting rows and examining columns are correct
Both counting rows and examining columns are correct
________ is the process of joining two or more tables and storing the result as a single table. Updating Querying Denormalization Normalization
Denormalization
To check for null values in a column in a table, use the SQL phrase ________. IS COUNT(NULL) IS NOT IS NULL
IS NULL
To count the number of rows in a table, use the SQL construct ________. SELECT * SELECT TOP n * SELECT COUNT(*) SELECT COUNT(TOP n)
SELECT COUNT(*)
To limit the number of rows retrieved from a table, use the SQL construct ________. SELECT TOP n * SELECT COUNT(TOP n) SELECT COUNT(*) SELECT *
SELECT TOP n *
A null value can indicate which of the following conditions? The value is incorrect. The value is appropriate but unknown. The value has been updated. The value can never be changed.
The value is appropriate but unknown.
A classic example of unneeded normalization is when we are dealing with ________. multivalued dependencies association patterns sales orders and line items ZIP codes
ZIP codes
The defining characteristic of BCNF is that a table is in BCNF if ________. all determinants are candidate keys all columns are consistent the primary key is a candidate key all rows are unique
all determinants are candidate keys
When you are given a set of tables and asked to create a database to store their data, the first step is to ________. assess the existing tables' structure and content design the database structure move the data into the new database create one or more new tables
assess the existing tables' structure and content
During the second step of assessing table structure, you are trying to determine ________. updatability efficiency candidate keys relationships
candidate keys
The SQL keyword IS NULL can be used to help ________. count the number of values in a column count the number of null values in a column count the number of columns in a table count the number of rows in a table
count the number of null values in a column
The SQL function COUNT ________. counts the number of tables in a database counts the number of columns in a table counts the number of rows in a table counts the number of updates to a database
counts the number of rows in a table
The second step in assessing table structure includes ________. counting rows examining columns examining data values counting rows and examining columns
examining data values
An advantage of denormalization is ________. faster design faster updating faster copying of data faster querying
faster querying
The SQL keyword TOP ________. limits the number of columns retrieved from a table limits the number of rows retrieved from a table limits the number of tables retrieved from a database limits the number of columns retrieved from a table and limits the number of tables retrieved from a database
limits the number of rows retrieved from a table
The disadvantages of normalization include ________. the elimination of modification anomalies the elimination of duplicated data more complex SQL for multitable subqueries and joins Both the elimination of modification anomalies and the elimination of duplicated data are correct
more complex SQL for multitable subqueries and joins
During the second step of assessing table structure, you are trying to determine ________. data types multivalued dependencies missing values subqueries
multivalued dependencies
Unlike the anomalies from functional dependencies, the anomalies from ________ are so serious that they should always be eliminated. multivalued dependencies sales orders and line items association patterns general purpose remarks columns
multivalued dependencies
For a number of reasons, ________ is not often an advantage for a read-only database. updating normalization denormalization Both updating and normalization are correct
normalization
A missing value is called a(n) ________. deleted value empty value missing value null value
null value
Read-only databases are used for ________. user account management data entry querying updating
querying
The presence of one or more foreign keys in a relation prevents ________. the elimination of modification anomalies the elimination of duplicated data more complex SQL for multitable subqueries and joins Both the elimination of modification anomalies and the elimination of duplicated data are correct
the elimination of duplicated data
The advantages of normalization include ________. simpler SQL queries more complex SQL for multitable subqueries and joins the elimination of duplicated data the elimination of modification anomalies
the elimination of modification anomalies
Reviewing the work done on a table that was created using existing data from multiple sources, you find that a column named Remarks has been included, and it is populated with inconsistent and verbose verbal data. This is an example of ________. the multivalued, multicolumn problem the inconsistent values problem the general-purpose remarks column problem the missing values problem
the general-purpose remarks column problem
The problem of misspelled data entries is really the same as ________. the multivalue, multicolumn problem the inconsistent values problem the missing values problem the general-purpose remarks column problem
the inconsistent values problem
When a table is created using existing data from multiple sources, you are likely to find that the different sources code data in slightly different ways. This is an example of ________. the multivalued, multicolumn problem the inconsistent values problem the missing values problem the general-purpose remarks column problem
the inconsistent values problem
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 ________. the multivalue, multicolumn problem the inconsistent values problem the missing values problem the general-purpose remarks column problem
the inconsistent values problem
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 multivalued, multicolumn problem the inconsistent values problem the missing values problem the general-purpose remarks column problem
the missing values 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 because the values are not known. This is an example of ________. the multivalued, multicolumn problem the inconsistent values problem the missing values problem the general-purpose remarks column problem
the missing values problem
When a table is created using existing data, you are likely to find that some data values have never been provided because any value there would be inappropriate. This is an example of ________. the multivalued, multicolumn problem the inconsistent values problem the missing values problem the general-purpose remarks column problem
the missing values problem
A table with columns PhoneNumber01, PhoneNumber02, and PhoneNumber03 is likely to have ________. the multivalue, multicolumn problem the inconsistent values problem the missing values problem the general-purpose remarks column problem
the multivalue, multicolumn problem
A form of multivalued dependency is found in ________. the multivalued, multicolumn problem the inconsistent values problem the missing values problem the general-purpose remarks column problem
the multivalued, multicolumn problem
