A UNION query is which of the following?

Related MCQs

• Any recursive view must be defined as the union of two subqueries: a                query that is nonrecursive and a                      query.
• A type of query that is placed within a WHERE or HAVING clause of another query is called
• A type of query that is placed within a WHERE or HAVING clause of another query is called
• Relational Algebra is a                      query language that takes two relations as input and produces another relation as an output of the query.
• Relational Algebra is a __________ query language that takes two relations as input and produces another relation as an output of the query.
• View the Exhibit and examine the data in the EMPLOYEES tables. Evaluate the following SQL statement: SELECT employee_id, department_id FROM employees WHERE department_id= 50 ORDER BY department_id UNION SELECT employee_id, department_id FROM employees WHERE department_id= 90 UNION SELECT employee_id, department_id FROM employees WHERE department_id= 10; What would be the outcome of the above SQL statement?
• Which of the following creates a temporary relation for the query on which it is defined?
• Which one of the following provides the ability to query information from the database and to insert tuples into, delete tuples from, and modify tuples in the database?
• Which of the following creates a virtual relation for storing the query?
• Suppose now that R(A,B:) and S(A,B:) are two relations with r and s tuples, respectively (again, not necessarily distinct). If m is the number of (not necessarily distinct) tuples in the result of the SQL query: R intersect S; Then which of the following is the most restrictive, correct condition on the value of m?