Consider the company database schema given above and especially the number of

tuples and pages for each relation. Consider now the following query:

Select Bname

From EMP E$,$ Building B$,$ In$\_$Building I

Where E$.$EID $<500$ and E$.$EID $=$ I.EID and B$.$BID $=$ I.BID

$($a$)[15$ points$]$ Write this query in the relational algebra.

$($b$)[20$ points$]$ If the database has an unclustered B$-$Tree index on EMP.EID, what is the best

plan you can find to execute this query? Show the query plan, including the costs for

each step and the total cost.