CASSANDRA CQL and Data Modeling

Question 1

What CQL statement is used to create a new keyspace in Cassandra?

Accepted Answer

CREATE KEYSPACE

Answer

CREATE KEYSPACE is the CQL command to define a new keyspace, specifying the replication strategy and factor.

Question 2

What is the difference between a partition key and a clustering key in a Cassandra primary key?

Accepted Answer

The partition key determines data distribution; clustering keys determine sort order within a partition

Answer

The partition key routes data to a node via consistent hashing, while clustering columns control the physical sort order of rows stored within that partition.

Question 3

Which CQL clause restricts the result set of a SELECT query to a specific partition?

Accepted Answer

WHERE partition_key = value

Answer

A WHERE clause filtering on the full partition key allows Cassandra to route the query directly to the correct node without a full cluster scan.

Question 4

What does the TTL (Time To Live) option do when inserting data in Cassandra?

Accepted Answer

Automatically deletes the data after the specified number of seconds

Answer

TTL marks data with an expiration time; Cassandra automatically creates a tombstone for that data once the TTL expires.

Question 5

What is a 'materialized view' in Cassandra?

Accepted Answer

A read-only cached copy of a base table with a different primary key for alternate access patterns

Answer

A materialized view is automatically maintained by Cassandra as a separate table built from a base table, allowing efficient queries on non-primary-key columns.

CASSANDRA - Apache Cassandra Database Practice Test

CASSANDRA - Apache Cassandra Database Practice Test

CASSANDRA CQL and Data Modeling