Amongst the ACID properties of a transaction, the 'Durability' property requires. that the changes made to the database by a successful transaction persist

www.ThinkITI.com

Home
MCQ
Search
Free Apps
Important
Study Groups
Contact Us
Policy

Home
MCQ
Objective Questions
Engineering
Computer Science
Computer Science Set-1
Databases
3

Databases MCQ with Answers

3) Amongst the ACID properties of a transaction, the 'Durability' property requires. that the changes made to the database by a successful transaction persist

Except in case of an operating system crash

Except in case of a disk crash

Except in case of a power failure

Always, even if there is a failure of any kind

Answer is:

Always, even if there is a failure of any kind

Databases MCQ with Answers

For more MCQ's Click Here

4) In a schema with attributes A, B, C, D and E following set of functional dependencies are given
A --> B
A -->C
CD —>E
B --> D
E—> A
Which of the following functional dependencies is the implied by the above set.

CD —> AC

BD --> CD

BC —> CD

AC —> BC

Answer is:

BD --> CD

5) Let R(A, B, C, D) be a relational schema with the following functional dependencies A —> B, B --> C ,

Gives a lossless join, and is dependency preserving.

Gives a lossless join, but is not dependency preserving

Does not give a loss less join, but is depency preserving

Does not give a lossless join and is not depency preserving

Answer is:

Gives a lossless join, and is dependency preserving.

6) Let R(A, B, C, D, E, P, G) be a relational schema in which the following functional dependencies are known to hold:
AB —> CD,
DE —> P,
C --> E,
P --> C and B —> G .
The relational schema R is

In BCNF

in 3NF, but not in BCNF

In 2NF, but not in 3NF

Not in 2NF

Answer is:

Not in 2NF

7) Consider the following set of functional dependencies on the schema (A, B, C)
A --> BC,
B —> C,
A —> B,
AB —> C
The canonical cover for this set is

A —> BC and B ---->C

A ----> BC and AB —> C

A —> BC and A —> B

A —> B and B —> C

Answer is:

A —> BC and B ---->C

Databases MCQ with Answers

For more MCQ's Click Here

3) Amongst the ACID properties of a transaction, the 'Durability' property requires. that the changes made to the database by a successful transaction persist

Always, even if there is a failure of any kind

Databases MCQ with Answers

Related Databases MCQ with Answers

4) In a schema with attributes A, B, C, D and E following set of functional dependencies are given A --> B A -->C CD —>E B --> D E—> A Which of the following functional dependencies is the implied by the above set.

BD --> CD

5) Let R(A, B, C, D) be a relational schema with the following functional dependencies A —> B, B --> C ,

Gives a lossless join, and is dependency preserving.

6) Let R(A, B, C, D, E, P, G) be a relational schema in which the following functional dependencies are known to hold: AB —> CD, DE —> P, C --> E, P --> C and B —> G . The relational schema R is

Not in 2NF

7) Consider the following set of functional dependencies on the schema (A, B, C) A --> BC, B —> C, A —> B, AB —> C The canonical cover for this set is

A —> BC and B ---->C

Databases MCQ with Answers

4) In a schema with attributes A, B, C, D and E following set of functional dependencies are given
A --> B
A -->C
CD —>E
B --> D
E—> A
Which of the following functional dependencies is the implied by the above set.

6) Let R(A, B, C, D, E, P, G) be a relational schema in which the following functional dependencies are known to hold:
AB —> CD,
DE —> P,
C --> E,
P --> C and B —> G .
The relational schema R is

7) Consider the following set of functional dependencies on the schema (A, B, C)
A --> BC,
B —> C,
A —> B,
AB —> C
The canonical cover for this set is