Q1. What do you mean by the term outer join? Describe the various types of outer joins with the help of illustrations.

Q2. Let consider the given relations for a database which keeps track of business trips of salespersons in a sales office:

SALESPERSON (SSN, Name, Start_Year, Dept_No)
TRIP (SSN, From_City, To_City, Departure_Date, Return_Date, Trip_ID)
EXPENSE (Trip_ID, Account#, Amount)

Specify the given queries in the relational algebra:

a) Find out the details (all attributes of TRIP relation) for trips whose expenses exceed $2000.

b) Find out the SSN of salesman who took trips to ‘Honolulu’.

c) Find out the total trip expenditures incurred by the salesman with SSN = ‘234-56-7890’.

Q3. Define the term view? How is it distinct from the table? prepare down the SQL syntax for making a view.