Specify the following queries in relational algebra on the database schema given in Exerci...

Specify the following queries in relational algebra on the database schema given in Exercise:

a. Give the details (all attributes of trip relation) for trips that exceeded $2,000 in expenses.

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b. Print the Ssns of salespeople who took trips to Honolulu.

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c. Print the total trip expenses incurred by the salesperson with SSN = ‘234-56-7890’.

Exercise

Consider the following relations for a database that 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)

A trip can be charged to one or more accounts. Specify the foreign keys for this schema, stating any assumptions you make.