Figuer:
CUSTOMER (Primary Key = CID) RENTALS (Primary Key = RTN)

question 62

Multiple Choice

Figuer:
CUSTOMER (primary key = CID) $\begin{array}{|l|l|l|l|l|}\hline \text { CID } & \text { CNAME } & \text { AGE } & \text { RESID\_CITY } & \text { Cregion } \\\hline 10 & \text { BLACK } & 40 & \text { SD } & \text { SD } \\\hline 20 & \text { GREEN } & 25 & \text { SD } & \text { SD } \\\hline 30 & \text { JONES } & 30 & \text { La Mesa } & \text { SD } \\\hline 40 & \text { MARTIN } & 35 & \text { LA } & \text { LA } \\\hline 50 & \text { SIMON } & 22 & \text { Pomona } & \text { LA } \\\hline 60 & \text { VERNON } & 60 & \text { Poway } & \text { SD } \\\hline\end{array}$ RENTALS (primary key = RTN) $$\begin{array} { | l | l | l | l | l | l | l | l | } \hline \text { CID } & \text { MAKE } & \text { DATE\_OUT } & \text { PICKUP } & \text { RETURN } & \text { RTN } & \text { VIN } & \text { DATE-IN } \\\hline 10 & \text { FORD } & \text { 10-Oct-00 } & \text { SD } & \text { SD } & 1 & \text { F1 } & \text { 01-Dec-00 } \\\hline 10 & \text { GM } & 01 - \text { Jan-01 } & \text { SD } & \text { LA } & 2 & & \\\hline 10 & \text { FORD } & 01 - \text { Feb-01 } & \text { LA } & \text { SD } & 3 & & \\\hline 20 & \text { NISSAN } & 07 - J u l - 00 & \text { SD } & & 4 & \text { N1 } & \\\hline 30 & \text { FORD } & 01 - J u l - 00 & \text { SD } & \text { SD } & 5 & \text { F2 } & 30 \text {-Nov-00 } \\\hline 30 & \text { GM } & 01 - \text {-Dec-00 } & \text { SD } & \text { SD } & 6 & \text { G1 } & \\\hline 40 & \text { FORD } & 01 - \text { Aug-00 } & \text { LA } & \text { LA } & 7 & \text { F3 } & \\\hline 50 & \text { GM } & 01 - \text { Sep-00 } & \text { LA } & \text { SD } & 8 & \text { G2 } & \\\hline 60 & \text { NISSAN } & 02 \text {-Jan-01 } & \text { SD } & \text { LA } & 9 & & \\\hline\end{array}$$ In the table RENTALS, RTN provides the rental number (it is the primary key) , CID refers to the CID in CUSTOMER, PICKUP is the city where the car was (or will be) picked up and Return is the city where the car was (or will be) returned, VIN is a foreign key that references the table CAR. The rental company has two branches, one in San Diego (SD) and one in Los Angeles (LA) . Cars are picked up and returned by the customers at these two locations.
RENTCOST $$\begin{array} { | l | l | } \hline \text { MAKE } & \text { COST } \\\hline \text { FORD } & 30 \\\hline \text { GM } & 40 \\\hline \text { NISSAN } & 30 \\\hline \text { TOYOTA } & 20 \\\hline \text { VOLVO } & 50 \\\hline\end{array}$$ In RENTCOST, COST shows the base cost of renting a given MAKE for one day.
CAR $$\begin{array} { | l | l | l | l | } \hline \text { VIN } & \text { MAKE } & \text { RENTED } & \text { AT } \\\hline \text { F1 } & \text { FORD } & \text { NO } & \text { SD } \\\hline \text { F2 } & \text { FORD } & \text { NO } & \text { SD } \\\hline \text { F3 } & \text { FORD } & \text { YES } & \text { IR } \\\hline \text { F4 } & \text { FORD } & \text { NO } & \text { LA } \\\hline \text { G1 } & \text { GM } & \text { YES } & \text { SD } \\\hline \text { G2 } & \text { GM } & \text { YES } & \text { SD } \\\hline \text { N1 } & \text { NISSAN } & \text { YES } & \text { LA } \\\hline \text { N2 } & \text { NISSAN } & \text { NO } & \text { LA } \\\hline \text { T1 } & \text { TOYOTA } & \text { NO } & \text { IR } \\\hline \text { T2 } & \text { TOYOTA } & \text { NO } & \text { IR } \\\hline \text { V1 } & \text { VOLVO } & \text { NO } & \text { LA } \\\hline \text { V2 } & \text { VOLVO } & \text { NO } & \text { LA } \\\hline\end{array}$$ The table CAR (primary key = VIN) provides information about each car, in particular if it is currently rented, and where its usual storage location is (attribute AT) .
CREATE VIEW CUST_SD AS
SELECT * FROM CUSTOMER
WHERE Cregion = 'SD'
CREATE VIEW CUST_40D AS
SELECT CNAME, RENTALS.MAKE, RENTCOST.COST
FROM CUSTOMER, RENTALS, RENTCOST
WHERE CUSTOMER.CID = RENTALS.CID
AND RENTALS.MAKE = RENTCOST.MAKE
AND RENTCOST < 40
CREATE VIEW Make_View (Make, NumRentals, Cregion, Storageat) AS
SELECT RENTALS.MAKE, Count (RTN) , Cregion, AT
FROM CUSTOMER, RENTALS, CAR
WHERE CUSTOMER.CID = RENTALS.CID
AND RENTALS.VIN = CAR.VIN
GROUP BY RENTALS.MAKE, Cregion, At
-UPDATE CUSTOMER SET AGE = AGE + 1
This command updates the following number of rows in the view CUST_SD:

• A) 3
• B) 4
• C) 6
• D) 0

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Definitions:

Personal Judgments

Opinions or decisions formed by individuals based on personal feelings, tastes, or opinions, often without external input or influence.

Certainty

The state of being confident and free from doubt about something, often implying a high degree of belief in the accuracy or truth of an outcome or fact.

Fully Informed

Being fully informed means having all the necessary and relevant information or knowledge about a particular subject or situation before making decisions.

Objective Probability

A measure of the likelihood of an event occurring, based on factual data and statistical analysis rather than personal judgment.