Software Design & Engineering Chapter 2 For relation Accounts and the first tuple

Exercise 2.2.1a

For relation Accounts, the attributes are:

Exercise 2.2.1b

For relation Accounts, the tuples are:

(12345, savings, 12000),

Exercise 2.2.1c

For relation Accounts and the first tuple, the components are:

123456 → acctNo

Exercise 2.2.1d

For relation Accounts, a relation schema is:

Exercise 2.2.1e

An example database schema is:

Accounts (

)

Exercise 2.2.1f

A suitable domain for each attribute:

acctNo → Integer

Exercise 2.2.1g

Another equivalent way to present the Account relation:

acctNo

balance

type

34567

25

savings

23456

1000

checking

12345

12000

savings

Another equivalent way to present the Customers relation:

idNo

firstName

lastName

account

805-333

Lena

Hand

23456

Exercise 2.2.2

Examples of attributes that are created for primarily serving as keys in a relation:

Exercise 2.2.3a

Exercise 2.2.3b

Exercise 2.2.3c

Exercise 2.3.1a

CREATE TABLE Product (

);

Exercise 2.3.1b

CREATE TABLE PC (

805-333

Lena

Hand

12345

901-222

Robbie

Banks

12345

);

Exercise 2.3.1c

CREATE TABLE Laptop (

);

Exercise 2.3.1d

CREATE TABLE Printer (

);

Exercise 2.3.1e

ALTER TABLE Printer DROP color;

Exercise 2.3.1f

Exercise 2.3.2a

CREATE TABLE Classes (

);

Exercise 2.3.2b

CREATE TABLE Ships (

);

Exercise 2.3.2c

);

Exercise 2.3.2d

CREATE TABLE Outcomes (

);

Exercise 2.3.2e

ALTER TABLE Classes DROP bore;

Exercise 2.3.2f

Exercise 2.4.1a

R1 := σspeed ≥ 3.00 (PC)

Exercise 2.4.1b

R1 := σhd ≥ 100 (Laptop)

Exercise 2.4.1c

R1 := σmaker=B (Product PC)

R2 := σmaker=B (Product Laptop)

R3 := σmaker=B (Product Printer)

1004

649

1005

630

1006

1049

2007

1429

Exercise 2.4.1d

R1 := σcolor = true AND type = laser (Printer)

model

3003

3007

Exercise 2.4.1e

R1 := σtype=laptop (Product)

F

G

Exercise 2.4.1f

maker

E

A

B

F

G

R1 := ρPC1(PC)

R2 := ρPC2(PC)

Exercise 2.4.1g

R1 := ρPC1(PC)

R2 := ρPC2(PC)

Exercise 2.4.1h

R1 := πmodel(σspeed ≥ 2.80(PC)) πmodel(σspeed ≥ 2.80(Laptop))

R2 := πmaker,model(R1 Product)

Exercise 2.4.1i

R1 := πmodel,speed(PC)

R2 := πmodel,speed(Laptop)

R3 := R1 R2

Exercise 2.4.1j

R1 := πmaker,speed(Product PC)

R2 := ρR2(maker2,speed2)(R1)

Exercise 2.4.1k

R1 := πmaker,model(Product PC)

R2 := ρR2(maker2,model2)(R1)

R3 := ρR3(maker3,model3)(R1)

R4 := ρR4(maker4,model4)(R1)

Exercise 2.4.2a

πmodel

Exercise 2.4.2b

πmaker

Exercise 2.4.2c

πmodel,price

Exercise 2.4.2d

πmodel

Exercise 2.4.2e

πmaker

–

Exercise 2.4.2f

πhd

Exercise 2.4.2g

πPC1.model,PC2.model

Exercise 2.4.2h

(maker = maker2 AND model <> model2)

πmaker

Exercise 2.4.2i

Product

–

πmaker

Exercise 2.4.2j

(maker3 = maker AND speed3 <> speed2 AND speed3 <> speed)

πmaker

Exercise 2.4.2k