What is the role of cardinality in an ER diagram?
It specifies the name of the relationship between entities
It indicates the number of instances of one entity that can be associated with instances of another entity
It defines the data type of an attribute
It determines the primary key of an entity
Which of these is crucial to consider when choosing data types for columns?
The username of the person creating the table.
The color scheme of the user interface.
The type of storage device used by the database server.
The kind of data the column will store and its expected size.
Referential integrity ensures that...
data is backed up regularly.
queries are optimized for performance.
relationships between tables remain consistent.
all columns in a table have unique values.
Which of the following best illustrates a table violating First Normal Form (1NF)?
An "Employee" table with EmployeeID as the primary key
A "Product" table with a ProductID, Name, and Price
An "Order" table with an OrderID and separate columns for each item ordered (e.g., Item1, Item2, Item3)
A "Customer" table with columns for CustomerID, Name, and Address
What is the role of a column in a database table?
To define a row in the table.
To link the table to another table.
To represent a specific attribute or characteristic of an entity.
To store the entire dataset of the table.
You are designing a schema to represent a relationship between 'Students' and 'Courses'. What type of relationship best describes this scenario?
Many-to-one
One-to-one
One-to-many
Many-to-many
In which scenario might denormalization be considered acceptable in database design?
To increase data redundancy
To enforce strict data integrity
To simplify the database schema
To improve query performance by reducing joins
Which of the following is NOT a characteristic of a table in First Normal Form (1NF)?
The table contains a foreign key referencing another table
A primary key uniquely identifies each row
There are no repeating groups of columns
Each column contains atomic values
Which of the following is a characteristic of a Dimension table in a Star Schema?
Typically has a small number of rows
Focuses on storing calculated metrics
Provides descriptive attributes about business entities
Contains highly transactional data
You have a table with columns for StudentID, StudentName, CourseID, and CourseName. StudentID determines StudentName, and CourseID determines CourseName. What normal form is this table in?
None of the above
First Normal Form (1NF)
Third Normal Form (3NF)
Second Normal Form (2NF)