User defined functions and Window functions Quiz

What does a SQL function do?

• Stores data
• Joins tables
• Calculates a result using inputs
• Deletes rows

Which of the following is a built-in SQL function?

• JOIN()
• RANK()
• ADD_TABLE()
• DROP()

Why would you create your own SQL function?

• To delete tables
• To avoid using SELECT
• To reuse custom logic
• To reduce memory usage

What keyword is used to define a new function in BigQuery?

• DEFINE FUNCTION
• MAKE FUNCTION
• CREATE FUNCTION
• FUNCTION NEW

In the function SAFE_DIVIDE(a, b), what does it help prevent?

• Repetition
• Syntax errors
• Division by zero
• Slow queries

In CREATE FUNCTION course17.margin(x, y), what is course17?

Which of these are good reasons to use user-defined functions?

• Reuse common logic
• Keep queries clean
• Enforce data consistency
• Format column names

What clause indicates a window function is being used?

• WHERE
• OVER
• WITH
• FUNCTION

Window functions always require a GROUP BY clause.

• True
• False

Which function can be used to assign a unique row number to each result?

• COUNT()
• RANK()
• ROW_NUMBER()
• SUM()