Correct Answer: a self-describing collection of related tables.
Explanation: A relational database is a collection of tables that are related to each other, and the structure and relationships are described within the database.
Data mining applications are used to accomplish all of the following tasks except ________.
- Correct Answer: Classify entities.
- Explanation: Data mining applications perform tasks like classification, prediction, clustering, and association rule mining. Classifying entities is one of the tasks performed by data mining applications.
Business Intelligence (BI) reporting systems can do which of the following operations?
- Correct Answer: Both Filter data and Group data.
- Explanation: BI reporting systems can filter and group data to provide users with meaningful insights into the data.
A relational database stores data in the form of ________.
SQL stands for ________.
- Correct Answer: Structured Query Language.
- Explanation: SQL is a standardized query language used for managing and manipulating relational databases.
Which of the following is not true about null values?
A. A null value can mean that no value for the field is appropriate.
B. A null value can mean that the value is known to be blank.
C. A null value is ambiguous.
D. A null value can mean that the value is unknown.
E. Null values cannot be avoided.
- Correct Answer: Null values cannot be avoided.
Explanation: Null values represent unknown or undefined data and cannot always be avoided in a database.
Which of the following terms is synonymous with "relation"?
A. Record
B. Tuple
C. Row
D. Table
E. Attribute
- Correct Answer: Table.
Explanation: In the context of a relational database, a relation is synonymous with a table.
The first step of the normalization process is to ________.
identify all the candidate keys of a relation
Explanation: Normalization involves identifying functional dependencies and eliminating redundancy in a database.
Identifying all candidate keys in the first step of normalization is crucial for reducing redundancy and ensuring data integrity. Candidate keys, minimal sets of attributes ensuring unique tuple identification, serve as the foundation for subsequent normalization steps, helping efficiently organize data and eliminate duplications.
When the primary key of one relation is placed into a second relation, it is called a ________.
- Correct Answer: Foreign key.
Explanation: A foreign key is a column or set of columns in a database table that refers to the primary key of another table.
Which symbol is used in standard SQL as a wildcard to represent a series of one or more unspecified characters?
- Correct Answer: % (percent sign).
Explanation: In SQL, the percent sign (%) is used as a wildcard for representing unspecified characters.
Which of the following is not one of the five SQL built-in functions?
A. SUM
B. MODE
C. COUNT
D. AVGE. MAX
- Correct Answer: MODE.
Explanation: MODE is not a standard SQL built-in function. Common SQL functions include SUM, AVG, COUNT, and MAX.
Given the table
CUSTOMER(CustID, Name, PhoneNum, AcctBalance)
what is the standard SQL query phrase to retrieve data for customers with an account balance greater than 50?
WHERE AcctBalance > 50
- Correct Answer: SELECT * FROM CUSTOMER WHERE AcctBalance > 50.
- Explanation: The WHERE clause is used to filter rows, and in this case, it retrieves data for customers with an account balance greater than 50.
The correct SQL query to retrieve data for customers with an account balance greater than 50 is to use the WHERE clause. The WHERE clause is used to filter rows based on a specified condition. In this case, you want to retrieve rows where the AcctBalance is greater than 50. So, the correct query is:
This query selects all columns (*) from the CUSTOMER table where the AcctBalance is greater than 50.
Given the table
CUSTOMER(CustID, Name, PhoneNum, AcctBalance)
what is the standard SQL query phrase to retrieve the Name and Phone Number of customers?
- Correct Answer: SELECT Name, PhoneNum FROM CUSTOMER.
Explanation: The SELECT statement is used to retrieve specific columns (Name and PhoneNum) from the CUSTOMER table.
Which of the following is not a basic element of the E-R Model?
B. Use cases
In the context of the Entity-Relationship (E-R) Model, use cases are not considered a basic element. The fundamental elements of the E-R Model are:
A. Identifiers (Attributes that uniquely identify entities within a set.)
B. Cardinalities (Express the relationships between entities, indicating how many instances of one entity are related to another.)
D. Entities (Objects or concepts that are represented in the database.)
E. Relationships (Associations between entities, showing how they are related.)
Use cases, on the other hand, are more associated with software engineering and systems analysis and design, often used to describe interactions between a system and external actors.
In crow's foot style E-R diagrams, a circle across the relationship line near an entity indicates ________.
A. a minimum cardinality of optional
In Crow's Foot style E-R diagrams, a circle across the relationship line near an entity indicates a minimum cardinality of mandatory. This means that each entity instance on the mandatory side of the relationship must be related to at least one instance on the other side of the relationship.
In Crow's Foot style Entity-Relationship diagrams, a circle across the relationship line near an entity signifies optional participation, indicating that instances of that entity are not required to be connected to instances on the other side of the relationship. This visual representation is a concise way of expressing minimum cardinality requirements and highlights the flexibility in relationships within a database schema.
The representation of the content, relationships, and constraints of the data needed to support the system requirements is the ________.
data model
Explanation: A data model represents the structure and relationships of the data required to support system requirements.
What relationship pattern is illustrated in the following schema?
EMPLOYEE (EmployeeID, OfficePhone, Manager)
Manager in EMPLOYEE must exist in EmployeeID in EMPLOYEE
Recursive relationship
In the given schema, the relationship pattern is a recursive relationship. This is indicated by the fact that the "Manager" attribute in the EMPLOYEE entity refers to the EmployeeID in the same EMPLOYEE entity. This kind of relationship is common when an entity is related to itself, such as in the case of employees being managed by other employees within the same EMPLOYEE entity.
Each attribute of an entity becomes a(n) ________ of a table.
A. column
Each attribute of an entity becomes a column in a table when the entity is represented in a relational database. The attributes of the entity are stored as columns, and each row in the table represents an instance of that entity.
Which of the following is not true about surrogate keys?
B. They are nonunique within a table.
Surrogate keys are unique identifiers within a table. They are typically system-generated and have no business meaning. Options A, B, C, and E are generally true about surrogate keys. They lack meaning to users (A), their values are usually not changed by the DBMS (B), they can pose challenges when combining databases (C), and they are provided by the system rather than users (E).
Computer systems fail for which of the following reasons except?
C. Databases randomly changed field values.
Computer systems can fail for various reasons, and the listed options cover common causes of failures. However, databases do not randomly change field values. Changes to data in databases occur due to intentional operations, whether performed by users or applications. Random changes would represent a serious issue and a failure in the integrity of the database system.
An ACID transaction is one that is all but ________.
B. guaranteed
An ACID transaction is one that is Atomic, Consistent, Isolated, and Durable. The term "guaranteed" is not typically associated with the ACID properties. The ACID properties describe the characteristics that guarantee reliable processing of database transactions.
Because SQL stored procedures allow and encourage code sharing among developers, stored procedures give database application developers the advantages of all except ________.
D. increased network throughput
Stored procedures provide benefits such as specialization among developers (A), less work (B), greater security (C), and standardized processing (D). However, they do not directly contribute to increased network throughput. In fact, stored procedures may involve network overhead when they are executed, as the procedure and its results may need to be transmitted between the database server and the client.
SQL views are used for all except ________.
C. to backup preexisting tables
SQL views are used for purposes such as:
A. to hide columns or rows
C. to display the results of computations
D. to hide complicated SQL syntax
E. to layer built-in functions
However, creating a view does not back up preexisting tables. Views are virtual tables that are based on the result of a SELECT query and do not store the data themselves. They provide a way to represent a subset of the data or a derived result set. If you want to back up tables, you would typically use backup and restore procedures specific to the database management system.
SQL statements used to construct views cannot contain ________.
E. the ORDER BY clause
In standard SQL, the ORDER BY clause is not allowed in the SQL statements used to construct views. The ORDER BY clause is used to sort the result set of a query, and since views are generally meant to represent a virtual table based on a SELECT query, adding an ORDER BY clause to a view is not allowed. If you need to sort the results when querying the view, you can use ORDER BY in the query that selects from the view.
Which type of join, although not included in standard SQL, was created to allow unmatched rows to appear in the result of a join operation?
A. OUTER JOIN
The OUTER JOIN, specifically the LEFT OUTER JOIN and RIGHT OUTER JOIN variations, allows unmatched rows from one or both of the tables to appear in the result set. This is in contrast to INNER JOIN, which only returns matched rows. The OUTER JOIN concept was introduced to address situations where you want to include unmatched rows from one or both tables in the result.
Information goods are not:
E. Easy to produce
A market is likely to tip when there are:
D. Strong economies of scale and low need for product variety
Which of the following is not an economic characteristic of information?
C. Low production costs
Network effects are associated with:
B. Demand-side economies of scale
Which of the following is a simple definition of the Internet?
C. A network of networks
Who owns the Internet?
C. The Internet is owned by millions of entities
Positive feedback refers to what?
C. An economic condition where the stronger gets stronger and the weaker get weaker
Tippy markets are associated with strong positive feedback.
True or False
True
What is a two-sided network?
A. A network that has two types of members
How is value created in networks?
A. Value is a function of the number of connected nodes
What is the revenue model of a firm that initially gives away its product or service for free and later attempts to charges for premium services?
B. Freemium
When categorizing eCommerce initiatives by transaction type, which category does an Online Travel Agency such as Expedia fall into?
B. Business-to-Consumer (B2C)
When categorizing eCommerce initiatives by transaction type, which category does electronic filing of income taxes with the federal government fall into?
A. eGovernment
What is the revenue model of Netflix.com?
A. Subscription
What have we defined as: “an online exchange of value”?
B. Electronic commerce
When categorizing eCommerce initiatives by company structure, which category does Walmart fall into?
A. Bricks and Clicks
When discussing the impacts of the Internet, we observed that marketplaces like Amazon or Alibaba are edging out the middlemen. We referred to this opportunity of digitalization as:
Disintermediation
With the term Web 2.0, we refer to the second coming of the services provided over the Internet. More specifically, Web 2.0 is mostly based on mobility and mobile applications.
True or False
False
What is the revenue model of Google?
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When categorizing eCommerce initiatives by company structure, which category does Spotify fall into?
