A table has a composite primary key (using two columns). What condition must be met for it to be considered in Second Normal Form (2NF)?
It must have no transitive dependencies
All columns must have unique values
No non-key attribute should be dependent on only part of the primary key
It must already be in 1NF
What is the primary difference between a Star Schema and a Snowflake Schema?
Snowflake Schemas normalize dimension tables.
Star Schemas have more joins.
Star Schemas are used for real-time analytics.
Snowflake Schemas don't use fact tables.
Why is defining a clear and well-structured schema important in database design?
It makes the database look visually appealing.
It simplifies data management, improves data integrity, and enhances query efficiency.
It eliminates the need for using SQL queries.
It automates the process of data entry.
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?
Third Normal Form (3NF)
First Normal Form (1NF)
None of the above
Second Normal Form (2NF)
In a Star Schema, what is the central table called that contains the key performance indicators (KPIs)?
Fact Table
Lookup Table
Entity Table
Dimension Table
Which of the following relationships is typically NOT implemented directly in a database but is often represented using an intermediary table?
One-to-One
Many-to-Many
All of the above
One-to-Many
Which of these is crucial to consider when choosing data types for columns?
The kind of data the column will store and its expected size.
The type of storage device used by the database server.
The username of the person creating the table.
The color scheme of the user interface.
Which of the following is NOT a valid action for cascading actions in SQL?
ON UPDATE CASCADE
ON DELETE CASCADE
ON SELECT CASCADE
ON INSERT CASCADE
What is the role of a column in a database table?
To store the entire dataset of the table.
To represent a specific attribute or characteristic of an entity.
To link the table to another table.
To define a row in the table.
To change the data type of a column in an existing table, which clause should be used with the ALTER TABLE statement?
TRANSFORM COLUMN
MODIFY COLUMN
UPDATE COLUMN
CHANGE COLUMN