WGU C175 Pre-Assessment
Terms in this set (50)
What is a broad definition of data?
Raw facts that are captured on printed or digital media
What are data?
Facts that are collected and stored in a database system
What is a determining characteristic of unstructured data?
It does not follow a data model.
Which is true about flat files?
They contain no internal hierarchical organization.
Which technology has no internal hierarchy?
How were data retrieved before database management systems?
Sequentially from simple files
In which two ways does a database management system environment increase effectiveness in working with data?
- It enables data sharing,
- It permits storage of vast volumes of data.
What is the uniquely identifiable element about which data can be categorized in an entity-relationship diagram?
Which classification is correct for the box marked "Quantity" in the given entity-relationship diagram?
Which data classification is an entity?
A salesperson is authorized to sell 12 products; a product can be sold by 10 salespersons.
Which kind of binary relationship is described in this example?
Which three kinds of rules for referential integrity are provided by modern relational database management systems?
Insert, Delete, Update
What is an important aspect of "referential integrity"?
Reference to data in one relation is based on values in another relation.
Sales data, detailing the customer names, products sold, and salespersons, is kept in a database.
Which kind of data in this database would qualify as intersection data related to both the product and salesperson entities?
What is an attribute or group of attributes that uniquely identify a tuple in a relation?
What is necessary for a primary key in one relation of a database to match with its corresponding foreign key in another relation of the same database?
A domain of values
What uniquely identifies each entity in a collection of entities but is not the primary key?
The alternate key
What is a term for a set of columns in a table that can uniquely identify any record in that table without referring to other data?
What happens to the original data in database indexing?
It is copied to the index.
Why are indexes created in a physical database design?
To retrieve data directly using a pointer.
Why is an index created on a database column?
To optimize data retrievals
Refer to the given SQL statement.
SELECT SPNUM, SPNAME
What is the correct line to add to the end of this statement to find salespersons with a commission percentage of 15?
Refer to the given SQL statement.
SELECT COMMPERCT, YEARHIRE
How should this statement be altered to retrieve the entire record instead of the commission percentage and year of hire?
Replace COMMPERCT, YEARHIRE with an asterisk
A manager asks an employee to list attributes of the customers that are headquartered in Los Angeles and that have a customer number higher than 1000. Refer to the given SQL statement prepared by this employee.
SELECT CUSTNUM, CUSTNAME, HQCITY
WHERE HQCITY='Los Angeles'
Which line should go at the end of this statement?
What is a key difference between the DISTINCT and ORDER BY statements, in SQL SELECT commands?
ORDER BY modifies the presentation of data results and DISTINCT filters data results.
Which SQL statement alphabetizes customer names within the same satellite-office city? ORDER or ALPHA?
ORDER BY SATCITY, CUSTNAME;
The given SQL statement is intended to list the names of the products of which salesperson Fox has sold more than 500 units.
FROM SALESPERSON, SALES, PRODUCT
Which set of lines should replace the question marks to make this statement work?
WHERE SALESPERSON.SPNUM=SALES.SPNUM AND SALES.PRODNUM=PRODUCT.PRODNUM
The given SQL statement is intended to query how many books there are with at least 800 pages from publishers in Los Angeles, United States.
AND CITY='Los Angeles'
AND COUNTRY='United States'
With which line should the question mark in this statement be replaced?
FROM PUBLISHER, BOOK
Which SQL statement will retrieve rows for all stores in Atlanta or Los Angeles or New York?
SELECT StoreID, City FROM Suppliers
WHERE City IN ('Atlanta', 'Los Angeles', 'New York');
Refer to the given SQL statement to answer the following question:
What would this SQL statement accomplish?
List all entries in the PRODUCT table.
What is a methodology for organizing attributes into tables?
What is the term for the value of one particular attribute associated with a specific single value of another attribute?
Which set of results should a company expect from implementing a business intelligence system?
Increased profitability and increased throughput
Which issue is focused on the loading component of extract, transform, load (ETL)?
Monitor refreshing volume and frequency
During which step in the extract, transform, load (ETL) process are raw data sets aggregated?
How is prediction distinguished from estimation in data mining?
Prediction classifies objects according to an expected future behavior.
Where does affinity grouping occur in data mining?
Which item represents unstructured data? A. Video training content. B. SQL tables of training instructors. C.Relational db for training tracking. D. Training db backup
A. Training Video Content
What is the entity-relationship diagram about a car rental agency showing?
One manufacturer created at least one of the agency's cars
Image shows Salesperson (with 1 bar) to Customers (with 1 bar).
How is the cardinality of the customers misrepresented?
There are many customers, but the cardinality indicates one customer.
Image shows Salesperson (with 2 bars) to Customer (with open circle and Crow's Feet). What is the correct way to read the modality on the right side of the association?
A minimum of zero customers
Project Code Employee No. Employee Name Department No. Department Name Hourly Rate
PC010 S10001 A. Smith L004 IT 22.00
PC010 S10030 L. Jones L023 Pensions 18.50
PC010 S21010 P. Lewis L004 IT 21.00
PC045 S10010 B. Jones L004 IT 21.75
PC045 S10001 A. Smith L004 IT 18.00
PC045 S31002 T. Gilbert L028 Database 25.50
PC045 S13210 W. Richards L008 Salary 17.00
PC064 S31002 T. Gilbert L028 Database 23.25
PC064 S21010 P. Lewis L004 IT 17.50
PC064 S10034 B. James L009 HR 16.50
In which state are the attributes shown?
First normal form
IDSt LastName IDProf Prof Grade
1 Mueller 3 Schmid 5
2 Meier 2 Borner 4
3 Tobler 1 Bernasconi 6
Which factor determines whether the table is in first normal form?
The attributes are all single valued.
ID Contract Code
1 Vinod 091
2 Rajiv 091
Code City Country
091 Bangalore India
The primary key in the first table is ID, and the primary key in the second is Code.
How advanced are the two tables in the normalization process?
Third normal form
Which characteristic points to the tables being in third normal form?
The tables are completely free of data redundancy.
A product-marketing company publishes an Internet-based newsletter about their new products to increase their customer base.
What is an advantage that this company will gain from investing in a relational database management system that will store customer information?
Improved query response times
One Customer (with Crows Feet) to One Product (with Crow's Feet)
Many customers to many products
Image shows Sales (with Crow's Feet and 1 bar) to Product (with 2 bars). What is the modality of the product?
At least one
Image shows 1 Salesperson box, One Salesperson (2 bars) to One Salesperson (2 bars). What kind of relationship does it depict?
Image shows Product (2 bars) solid line to (1 bar + Crow's Feet) Component (1 bar + Crow's Feet) solid line back to Product (2 bars)