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Advanced-rdbms-concepts Questions Set 3:

Quiz Mode

The join operations that do not retain mismatched tuples are called _________ joins.

outer

natural

full outer

inner

Solution:

Which of the following is NOT a superkey in a relational schema with attributes V, W, X, Y, Z and primary key V, Y?

V X Y Z

V W X Z

V W X Y

V W X Y Z

Solution:

Consider the relation scheme R = {E, F, G, H, I, J, K, L, M, M} and the set of functional dependencies {{E, F} -> {G}, {F} -> {I, J}, {E, H} -> {K, L}, K -> {M}, L -> {N} on R. What is the key for R?

{E, F}

{E, F, H}

{E, F, H, K, L}

{E}

Solution:

Consider the following transaction involving two bank accounts x and y.
read(x); x := x – 50; write(x); read(y); y := y + 50; write(y)
The constraint that the sum of the accounts x and y should remain constant is that of

Atomicity

Consistency

Isolation

Durability

Solution:

What is a foreign key?

A foreign key is a primary key of a relation which is an attribute in another relation

A foreign key is a superkey of a relation which is an attribute in more than one other relations

A foreign key is an attribute of a relation that is a primary key of another relation

A foreign key is the primary key of a relation that does not occur anywhere else in the schema

Solution:

Let S be the following schedule of operations of three transactions T₁, T₂ and T₃ in a relational database system:
R₂(Y), R₁(X), R₃(Z), R₁(Y), W₁(X), R₂(Z), W₂(Y), R₃(X), W₃(Z)
Consider the statements P and Q below :
P : S is conflict serializable
Q : If T₃ commits before T₁ finishes, then S is recoverable

P is true and Q is false

Both P and Q are false

Both P and Q are true

P is false and Q is true

Solution:

Let ri(z) and wi(z) denote read and write operations respectively on a data item z by a transaction Ti. Consider the following two schedules.
S1: r1(x)r1(y)r2(x)r2(y)w2(y)w1(x) S2: r1(x)r2(x)r2(y)w2(y)r1(y)w1(x)
Which one of the following options is correct?

S1 is conflict serializable, and S2 is not conflict serializable

S1 is not conflict serializable, and S2 is conflict serializable

Both S1 and S2 are conflict serializable

Neither S1 nor S2 is conflict serializable

Solution:

Consider the following relation
Cinema (theater, address, capacity)
Which of the following options will be needed at the end of the SQL query
SELECT P1. address FROM Cinema P1
Such that it always finds the addresses of theaters with maximum capacity?

WHERE P1. Capacity> = All (select P2. Capacity from Cinema P2)

WHERE P1. Capacity> = Any (select P2. Capacity from Cinema P2)

WHERE P1. Capacity > All (select max(P2. Capacity) from Cinema P2)

WHERE P1. Capacity > Any (select max (P2. Capacity) from Cinema P2)

Solution:

The following functional dependencies hold true for the relational schema R{V, W, X, Y, Z}:
V -> W VW -> X Y -> VX Y -> Z
Which of the following is irreducible equivalent for this set of functional dependencies?

Solution:

A database of research articles in a journal uses the following schema.
(VOLUME, NUMBER, STARTPGE, ENDPAGE, TITLE, YEAR, PRICE)
The primary key is (VOLUME, NUMBER, STARTPAGE, ENDPAGE) and the following functional dependencies exist in the schema.
(VOLUME, NUMBER, STARTPAGE, ENDPAGE) → TITLE
(VOLUME, NUMBER) → YEAR
(VOLUME, NUMBER, STARTPAGE, ENDPAGE) → PRICE
The database is redesigned to use the following schemas.
(VOLUME, NUMBER, STARTPAGE, ENDPAGE, TITLE, PRICE)
(VOLUME, NUMBER, YEAR)
Which is the weakest normal form that the new database satisfies, but the old one does not?

1NF

2NF

3NF

BCNF

Advanced-rdbms-concepts Questions Set 3:

The join operations that do not retain mismatched tuples are called _________ joins.

Solution:

Which of the following is NOT a superkey in a relational schema with attributes V, W, X, Y, Z and primary key V, Y?

Solution:

Consider the relation scheme R = {E, F, G, H, I, J, K, L, M, M} and the set of functional dependencies {{E, F} -> {G}, {F} -> {I, J}, {E, H} -> {K, L}, K -> {M}, L -> {N} on R. What is the key for R?

Solution:

Consider the following transaction involving two bank accounts x and y.
read(x); x := x – 50; write(x); read(y); y := y + 50; write(y)
The constraint that the sum of the accounts x and y should remain constant is that of

Solution:

What is a foreign key?

Solution:

Solution:

Let ri(z) and wi(z) denote read and write operations respectively on a data item z by a transaction Ti. Consider the following two schedules.
S1: r1(x)r1(y)r2(x)r2(y)w2(y)w1(x) S2: r1(x)r2(x)r2(y)w2(y)r1(y)w1(x)
Which one of the following options is correct?

Solution:

Consider the following relation
Cinema (theater, address, capacity)
Which of the following options will be needed at the end of the SQL query
SELECT P1. address FROM Cinema P1
Such that it always finds the addresses of theaters with maximum capacity?

Solution:

The following functional dependencies hold true for the relational schema R{V, W, X, Y, Z}:
V -> W VW -> X Y -> VX Y -> Z
Which of the following is irreducible equivalent for this set of functional dependencies?

Solution:

Solution:

Related Question Sets:

Related Topics:

Advanced-rdbms-concepts Questions Set 3:

The join operations that do not retain mismatched tuples are called _________ joins.

Solution:

Which of the following is NOT a superkey in a relational schema with attributes V, W, X, Y, Z and primary key V, Y?

Solution:

Consider the relation scheme R = {E, F, G, H, I, J, K, L, M, M} and the set of functional dependencies {{E, F} -> {G}, {F} -> {I, J}, {E, H} -> {K, L}, K -> {M}, L -> {N} on R. What is the key for R?

Solution:

Consider the following transaction involving two bank accounts x and y.read(x); x := x – 50; write(x); read(y); y := y + 50; write(y) The constraint that the sum of the accounts x and y should remain constant is that of

Solution:

What is a foreign key?

Solution:

Solution:

Let ri(z) and wi(z) denote read and write operations respectively on a data item z by a transaction Ti. Consider the following two schedules.S1: r1(x)r1(y)r2(x)r2(y)w2(y)w1(x) S2: r1(x)r2(x)r2(y)w2(y)r1(y)w1(x) Which one of the following options is correct?

Solution:

Consider the following relation Cinema (theater, address, capacity) Which of the following options will be needed at the end of the SQL querySELECT P1. address FROM Cinema P1 Such that it always finds the addresses of theaters with maximum capacity?

Solution:

The following functional dependencies hold true for the relational schema R{V, W, X, Y, Z}:V -> W VW -> X Y -> VX Y -> Z Which of the following is irreducible equivalent for this set of functional dependencies?

Solution:

Solution:

Related Question Sets:

Related Topics:

Consider the following transaction involving two bank accounts x and y.
read(x); x := x – 50; write(x); read(y); y := y + 50; write(y)
The constraint that the sum of the accounts x and y should remain constant is that of

Let ri(z) and wi(z) denote read and write operations respectively on a data item z by a transaction Ti. Consider the following two schedules.
S1: r1(x)r1(y)r2(x)r2(y)w2(y)w1(x) S2: r1(x)r2(x)r2(y)w2(y)r1(y)w1(x)
Which one of the following options is correct?

Consider the following relation
Cinema (theater, address, capacity)
Which of the following options will be needed at the end of the SQL query
SELECT P1. address FROM Cinema P1
Such that it always finds the addresses of theaters with maximum capacity?

The following functional dependencies hold true for the relational schema R{V, W, X, Y, Z}:
V -> W VW -> X Y -> VX Y -> Z
Which of the following is irreducible equivalent for this set of functional dependencies?