(Solved): Example database (Ch. 04) Consider the following query, the join graph and the distribution of the ...

Example database (Ch. 04) Consider the following query, the join graph and the distribution of the relations and/or fragmentations to the sites depicted below. We assume all records have same size. $\mathrm{size}(EMP?ASG)=2000$, and size(ASG $?$ PROJ $)=1000$. The goal is to minimize communication cost. SELECT ENAME FROM EMP, ASG, PROJ WHERE PROJ.PNO = ASG.PNO AND EMP.ENO = ASG.ENO 1) Which join do we need to perform first, either EMP $?$ ASG or ASG $?$ PROJ? Why? 2) Explain how to perform the first join in terms of which relation needs to be sent to which site. You do not need to consider semijoin. 3) Explain how to perform the second join which is using the result of the first join in terms of which relation(s) need(s) to be sent to which site(s). You do not need to consider semijoin.