A university database contains an Instructor record type with fields:ID, name, dept_name, and salary. An HR application allows department heads to view only the instructor names and departments, but not salaries.Which level of data abstraction is primarily being applied in this case?

Section schema: section (course_id, sec_id, semester, year, building, room_number, time_slot_id)  To list all courses that were taught in Fall 2017 or Spring 2018 (or both), which of the following relational algebra expressions is correct?

A relation Instructor(ID, name, dept_name, salary) is stored in a university database. Which relational algebra expression retrieves the names of instructors in the ‘Computer Science’ department who earn more than $80,000?

Which scenario best illustrates why a view is used?

A university registrar wants a list of all departments that currently have instructors earning more than $90,000. Which query will correctly produce this list without repeating any department names?

A university administrator wants to list all instructors by department, and within each department, in descending order of their names. Which query will produce the desired result?

A university database contains the table: dept_name instructor_id salary Comp. Sci. 101 90000 Comp. Sci. 102 95000 Physics 103 70000 A student executes this query: select dept_name, instructor_id, avg(salary) from instructor group by dept_name;

A banking application sends a query to retrieve all customers with balances above $10,000. Before the data is fetched, the system first checks query syntax, determines an efficient access path using indexes, and creates an execution plan. Which database system component performs these steps?

A university database has a relation Instructor(ID, name, dept_name, salary). Two instructors can have the same name but never the same ID. Which of the following sets is a candidate key for this relation?

A factor that could determine the winning construction of the January 6, 2021 protests is collective values.