For the following PC relation, suppose we compute the projection speed (PC). What is the value of this expression as a set? As a bag? What is the average value of tuples in this projection, when treated as a set? As a bag? (20 points)

model	speed	ram	hd	price
1001	2.66	1024	250	2114
1002	2.10	512	250	995
1003	1.42	512	80	478
1004	2.80	1024	250	649
1005	3.20	512	250	630
1006	3.20	1024	320	1049
1007	2.20	1024	200	510
1008	2.20	2048	250	770
1009	2.00	1024	250	650
1010	2.80	2048	300	770
1011	1.86	2048	160	959
1012	2.80	1024	160	649

1013 3.06 512 80 529 For two relations:

R (A, B) = {(0,1), (2,3), (0,1), (2,4), (3,4)}

S(B, C) = {(0,1), (2,4), (2,5), (3,4), (0,2), (3,4)}

Compute the following: (40 points)

B+1,C-1 (S); b) B,C (S); c) (R); d) A,SUM(B) (R); e) R OUTERJOIN R.B < S.B S

List the isolation levels of transactions and explain their differences in your own words (10 points).

From the following base tables: (20 points)

MovieStar (name, address, gender, birthdate)

MovieExec (name, address, cert#, netWorth)

Studio (name, address, presC#)

Construct the following views:

A view RichExec giving the name, address, certificate number and net worth of all executive with a net worth of at least $10,000,000.

A view StudioPres giving the name, address, and certificate number of all executive who are studio presidents.

For the same base tables in Question 5, declare indexes on the following attributes or combination of attributes (10 points).

address of MovieExec

gender and birthdate