Task $1$

We have two relations:

Student

NetID Dept

$123$ Mgmt

$321$ Fin

TeachingAssistant

NetID Dept

$123$ Mgmt

$456$ Ops

Please create table to show what is

Student $$ TeachingAssistant

Student $$ TeachingAssistant

Student $$ TeachingAssistant

Task $2$:

Suppose we have the following two tables

TA

NetID Salary Dept

$123,100000Mgmt$

$321200000$ Fin

$456,150000$ Ops

$678,120000$Ops

$789310000$ Fin

DeptContact

Dept Phone

Mgmt $123$

Ops $1232$

Fin $,12314$

Please translate the following relational algebra into SQL code

$1.$

$2.$

$3.$

$4.$

Task $3$

Following Task $2,$ please answer if the following two query plans return the same result? And if yes, which runs faster?

Plan $1$:

Plan $2$: