Question 1

What is a NOT a valid limitation for Cassandra counters?

Options :

A : Counters cannot be used for columns part of the PRIMARY KEY of a table.

B : Counter values cannot go below zero.

C : The value of a counter cannot be set.

D : A table that contains a counter can only contain counters.

Answer: B

Question 2

You have a single datacenter 10-node cluster with a replication factor of 3.

What can NOT happen on an UPDATE query for one single row, when the consistency level is set to ONE?

Options :

A : An incoming write will go only to the first node that owns the requested row.

B : Only one node can properly complete the write

C : The other two replicas can miss the write.

D : Coordinator returns control back to the client after one single write is confirmed.

Answer: A

Question 3

Consider the following keyspace definition:

1. CREATE KEYSPACE mykeyspace

2. WITH replication = {'class': 'NetworkTopologyStrategy', 'DC1': 3, 'DC2': 3};

DC1 has 4 nodes active and 2 down, DC2 has 3 nodes active and one down.

Which of the next statements is true?

Options :

A : A request with LOCAL_QUORUM on a healthy DC2 node will be handled by DC1.

B : A request with LOCAL_QUORUM on a healthy DC2 node will succeed.

C : A request with QUORUM on a healthy DC2 node will fail.

D : A request with LOCAL_QUORUM on a healthy DC1 node will fail.

Answer: B

Question 4

Define the primary key for accounts_by_user:

Options :

A : PRIMARY KEY (username, account_number ASC)

B : PRIMARY KEY ((username), account_number)

C : PRIMARY KEY (username, (account_number))

D : PRIMARY KEY ((username, account_number))

Answer: B

Question 5

What is wrong with this user-defined type (UDT) definition?

1. CREATE TYPE States (

2. id uuid PRIMARY KEY,

3. name text

4. );

Options :

A : UDTs cannot declare primary keys.

B : UUID is not a valid CQL data type.

C : Must start by CREATE TYPE IF NOT EXISTS.

D : The name should be all lower cases.

Answer: A