Chapter 4 - LOGICAL DATABASE DESIGN AND THE RELATIONAL MODELRELATIONAL MODE Flashcards
What is the primary purpose of logical database design?
To create a model that accurately represents the data requirements of the business.
True or False: The relational model organizes data into tables.
True
Fill in the blank: In a relational database, each table is also known as a ________.
relation
What are the main components of a relational database?
Tables, rows, columns, and relationships.
What does a primary key do in a relational database?
It uniquely identifies each record in a table.
Multiple Choice: Which of the following is NOT a type of relationship in a relational database? A) One-to-One B) One-to-Many C) Many-to-Many D) None
D) None
What is a foreign key?
A field in one table that uniquely identifies a row of another table.
True or False: Normalization is the process of organizing a database to reduce redundancy.
True
What is the purpose of normalization?
To eliminate data redundancy and ensure data integrity.
Fill in the blank: The first normal form (1NF) requires that each column in a table contains ________.
atomic values
What is a composite key?
A key that consists of two or more attributes that together uniquely identify a record.
Multiple Choice: Which normal form addresses transitive dependencies? A) 1NF B) 2NF C) 3NF D) BCNF
C) 3NF
What is referential integrity?
A property that ensures that relationships between tables remain consistent.
True or False: A relation can contain duplicate rows.
False
What is the role of an Entity-Relationship (ER) model in database design?
To visually represent the data and relationships in a database.
Fill in the blank: An entity in an ER model represents a ________ in the real world.
thing or object
What does the term ‘cardinality’ refer to in database design?
The number of instances of one entity that can or must be associated with each instance of another entity.
Multiple Choice: Which of the following describes a ‘many-to-many’ relationship? A) Each student can enroll in many courses, and each course can have many students. B) Each employee can work in only one department. C) Each customer can place only one order. D) None of the above.
A) Each student can enroll in many courses, and each course can have many students.
What is denormalization?
The process of combining tables to improve read performance, often at the cost of write performance.
True or False: A view in a relational database is a virtual table that is based on the result set of a query.
True
What is the purpose of using indexes in a database?
To improve the speed of data retrieval operations.
Fill in the blank: SQL stands for ________.
Structured Query Language
What is the difference between a clustered index and a non-clustered index?
A clustered index determines the physical order of data in a table, while a non-clustered index creates a separate structure for faster lookups.
Multiple Choice: Which SQL statement is used to retrieve data from a database? A) INSERT B) SELECT C) UPDATE D) DELETE
B) SELECT
What does ACID stand for in the context of database transactions?
Atomicity, Consistency, Isolation, Durability.
True or False: A transaction is a sequence of operations performed as a single logical unit of work.
True
What is the purpose of a database schema?
To define the structure of a database, including tables, fields, and relationships.
Fill in the blank: The ________ clause in SQL is used to filter records.
WHERE