Given the following relations
Vehicle (Reg_no, make, colour)
Person(eno, name, address)
Owner(eno, reg_no)
Write expressions in the relational algebra to answer the following queries:-
(i) List the reg_no of vehicles owned by John.
(ii) List the names of persons who own maruti cars.
(iii) List all the red coloured vehicle.

Ans: (i) π reg_no (σ name='John' (PERSON OWNER)) // list of ref_no of vehicles
(ii) π name (σ make='maruti' (PERSON OWNER VEHICAL)) // list of names of persons
(iii) σ colour='red' (VEHICAL) // list all the red color