Write SQL queries for the following sentences considering the given relational schema of university database.

1. Suppose full name of the instructors are stored as atomic value where parts of names are separated by blank space. Find all instructors who has last name Rob.

2. Find the name of those departments whose total salary of the instructors is greater than 600000.

3. Delete courses having ID beginning with CS

student takes ID course id sec_id semester year grade ID Tarte dept_name tot_cred course advisor section course id sec id semester year building room_no time_slot_id course id title dept_name credits department dept_name building budget time_slot time_slot_id day start time end_time prereg instructor classroom building room no capacity COKTse id prereg id ID name dept_name salary teaches ID course_id sec id semester year