Reference no: EM13934310
Consider the following relations containing airline flight information: Flights(flno: integer, from: string, to: string, distance: integer, departs: time, arrives: time) Aircraft(aid: integer, aname: string, cruisingrange: integer) Certified(eid: integer, aid: integer)
Employees(eid: integer, ename: string, salary: integer)
Note that the Employees relation describes pilots and other kinds of employees as well; every pilot is certified for some aircraft (otherwise, he or she would not qualify as a pilot), and only pilots are certified to fly.
Write the following queries in relational algebra, tuple relational calculus, and domain relational calculus. Note that some of these queries may not be expressible in relational algebra (and, therefore, also not expressible in tuple and domain relational calculus)! For such queries, informally explain why they cannot be expressed. (See the exercises at the end of Chapter 5 for additional queries over the airline schema.)
1. Find the eids of pilots certified for some Boeing aircraft.
2. Find the names of pilots certified for some Boeing aircraft.
3. Find the aids of all aircraft that can be used on non-stop flights from Bonn to Madras.
4. Identify the flights that can be piloted by every pilot whose salary is more than $100,000.
5. Find the names of pilots who can operate planes with a range greater than 3,000 miles but are not certified on any Boeing aircraft.
6. Find the eids of employees who make the highest salary.
7. Find the eids of employees who make the second highest salary.
8. Find the eids of employees who are certified for the largest number of aircraft.
9. Find the eids of employees who are certified for exactly three aircraft.
10. Find the total amount paid to employees as salaries.
11. Is there a sequence of flights from Madison to Timbuktu? Each flight in the sequence is required to depart from the city that is the destination of the previous flight; the first flight must leave Madison, the last flight must reach Timbuktu, and there is no restriction on the number of intermediate flights. Your query must determine whether a sequence of flights from Madison to Timbuktu exists for any input Flights relation instance.
|
Description of how you collected the data
: References to data sources used for your study. Although you will work as a group to undertake your analysis, you must submit an individual report. The text, graphs, tables etc included in your report should be your own work. Data have been collec..
|
|
How address different sexual orientation as group supervisor
: Does anyone have any thoughts or comments on how to address different sexual orientations (LGBT) as the group supervisor? My understanding is the strength of the group comes from the interaction and acceptance of each member. Any thoughts on how t..
|
|
Fundamental quality management tools and techniques
: Before starting this assessment activity, read the full assessment description, marking criteria, submission requirements and guidance provided in the course textbook and below.
|
|
Presentation of data for the senior investment advisers
: Having completed your Graduate Degree from Cambridge, you have just got a job at a small investment advisory firm. Your firm recommends investment funds to Self-Managed Super Fund (SMSF) clients based on their risk and return characteristics.
|
|
Find the eids of employees who make the highest salary
: Find the eids of employees who make the highest salary. Find the eids of employees who make the second highest salary.
|
|
Meeting the customer requirements
: Meeting the customer requirements (Oakland 2003) is a reasonable definition of quality. b. Customer satisfaction means we can wrap up our projects more rapidly (Frame 2002, quoted in Reid 2013a) c. Not doing it right the first time at every stage ..
|
|
What is the role of an i/o psychologist in an organization
: How are I/O psychologists trained? What is the role of an I/O psychologist in an organization? How will the role of I/O psychologists change/evolve in the next several years?
|
|
Full assessment description-marking criteria
: Before starting this assessment activity, read the full assessment description, marking criteria, submission requirements and guidance provided on the course textbook. Assessment Guidance Then check the assessment discussions on the forum(s) for a..
|
|
Use excel to set up an amortization schedule
: A customer with a trade-in offers the store a $260 cash price for the cabinet. Is that a better deal (for the customer) than the store is offering? On Mary's 16th birthday, her parents invest on her behalf an amount of $5,000 into an account that ..
|