Consider the advisor? relation shown in Figure 2.8, with s _id? as the primary key of advisor . Suppose a student can have more than one advisor. Then, would s_id? still be a primary key of the advisor? relation? If not, what should the primary key of advisor? be?

Reference Figure 2.8:

section course id sec id semester year building room_no time_slot_id classroom building room no capacity takes ID course id sec id semester year grade time_slot time slot id day start time end_time teaches ID course_id sec id semester year course course id title dept_name credits prereq course id prereq id student ID name dept_name tot cred department dept name building budget instructor ID name dept_name salary Figure 2.8 Schema diagram for the university database. advisor s id i_id