CS6400 Exam Prep Questions and Answers
Verified 100% Correct
what many superkeys can be a relation? - ✔✔degree of relation
what is a domain? - ✔✔domain is the array of possible values a attribute can have
how is domain different from type? - ✔✔type is the kind of values, while domain is the
array of values within that kind. Example: type of 'color' would have domain of {"red, blue,
red.....}
Can multiple domains exist in a relation? - ✔✔Yes, example: if multiple integers existed,
then the domain of all positive/negative integers would be present
Can multiple primary keys exist? - ✔✔No, but a primary key can consist of
multiple candidate keys, and within the primary key can exist multiplesuperkeys
How many unique fields can exist in the following:
candidate key:
superkey:
primary key: - ✔✔1.) 1
2.)
3.) 1 or more
In the relation R(A1,A2,A3), how many of the following can exist?
, Candidate:
Superkey:
primary key: - ✔✔1.) Do not know because their is no uniqueness constraint
2.)
with the following binary operation, R x S, what is the resulting # of tuples? - ✔✔
by default, how many superkeys are in a relation - ✔✔1, all of the attributes together
superkey vs minimal superkey? - ✔✔TYpically superkey
If R(A1, A2, A3,A4) is a relation and A1 is a primary key, how many super keys are there -
✔✔It will alwyas be: the Primary key + Primary key & another column combinations; so
with the following
1.) A1
2.) A1, A2
3.) A1, A3
4.) A1, A4
5.) A1,A2,A3
6.) A1, A3, A4
7.) A1,A2,A3,A4
minimal superkey vs candidate key? - ✔✔They are the same
If R(A1, A2, A3,A4) is a relation and A1 and A2 are a primary key, how many super keys
are there - ✔✔1.) A1, A2
2.) A1, A2, A3
3.) A1, A2, A4
Verified 100% Correct
what many superkeys can be a relation? - ✔✔degree of relation
what is a domain? - ✔✔domain is the array of possible values a attribute can have
how is domain different from type? - ✔✔type is the kind of values, while domain is the
array of values within that kind. Example: type of 'color' would have domain of {"red, blue,
red.....}
Can multiple domains exist in a relation? - ✔✔Yes, example: if multiple integers existed,
then the domain of all positive/negative integers would be present
Can multiple primary keys exist? - ✔✔No, but a primary key can consist of
multiple candidate keys, and within the primary key can exist multiplesuperkeys
How many unique fields can exist in the following:
candidate key:
superkey:
primary key: - ✔✔1.) 1
2.)
3.) 1 or more
In the relation R(A1,A2,A3), how many of the following can exist?
, Candidate:
Superkey:
primary key: - ✔✔1.) Do not know because their is no uniqueness constraint
2.)
with the following binary operation, R x S, what is the resulting # of tuples? - ✔✔
by default, how many superkeys are in a relation - ✔✔1, all of the attributes together
superkey vs minimal superkey? - ✔✔TYpically superkey
If R(A1, A2, A3,A4) is a relation and A1 is a primary key, how many super keys are there -
✔✔It will alwyas be: the Primary key + Primary key & another column combinations; so
with the following
1.) A1
2.) A1, A2
3.) A1, A3
4.) A1, A4
5.) A1,A2,A3
6.) A1, A3, A4
7.) A1,A2,A3,A4
minimal superkey vs candidate key? - ✔✔They are the same
If R(A1, A2, A3,A4) is a relation and A1 and A2 are a primary key, how many super keys
are there - ✔✔1.) A1, A2
2.) A1, A2, A3
3.) A1, A2, A4
