Explain the θ-join and equijoin
Refer tables Car and Boat which list models of cars and boats and their relevant prices. Assume a customer wants to buy a car and a boat, but she doesn't wish to spend more money for the boat as compared to for the car. The θ -join on the relation CarPrice > BoatPrice generates a table with all the probable options. If the condition employs equality operator then it is also termed as equijoin.