Final answer:
The statement is true; the MINUS set operator is used in SQL to find the unique rows returned by the first query that are not present in the second query, assuming both queries return the same number and type of columns.
Step-by-step explanation:
The statement that the MINUS set operator is used to display rows that were uniquely returned by the first query in the set is true. The MINUS operator in SQL is used to return all rows in the first select statement that are not returned by the second select statement. It's important to note that the columns and data types in both select statements must be the same for the MINUS operator to work effectively.
For example, if we have two queries: Query A selects all students from a "Students" table, and Query B selects students who have registered for a "Science" class. The MINUS operation between these two queries would return the students who are in the "Students" table but have not registered for the "Science" class. This demonstrates how the MINUS operator isolates unique records in the first query that are not found in the subsequent query.
An important consideration when using MINUS is that it eliminates duplicates and the result set is the distinct rows from the first query that are not in the second query. It is often used in data analysis and database management to find differences between datasets.