b,d

b,c

a

c,d

a,b

b,c

External

Both A and B

Internal

b,d

a

b,c

Only Q1 and Q2 are

equivalent

Q1 is equivalent to Q2

and Q3 is equivalent to Q4

 None of the above.

Only Q3 and Q4 are

equivalent.

A user of the database system

An object that will be composed of multiple attributes

An object that will have many instances in the database

b,c

b,d

a

employee (id#, emp name) is a relation instance

{12, Jessica} is neither a relation schema nor an instance of a relation

{12, Jessica} is an instance of a relation schema

b,c

a,b

c,d

numeric

 sap

varchar2