CASSANDRA Skills 5

Question 1

Which Cassandra feature lets you define a secondary sort order within a partition using the PRIMARY KEY definition?

Accepted Answer

Clustering columns

Answer

Clustering columns are the non-partition components of the primary key and determine the sort order of rows within a partition.

Question 2

You need to read the most recent 10 events for a user from a time-ordered table. Which CQL clause should you use?

Accepted Answer

LIMIT 10

Answer

The LIMIT clause in CQL restricts the number of rows returned per partition, making it efficient for paginated or top-N queries.

Question 3

What is a 'token-aware' load balancing policy in a Cassandra driver, and why is it preferred?

Accepted Answer

It routes requests to the node that owns the relevant partition, reducing hops

Answer

Token-aware routing sends queries directly to the replica that owns the data, avoiding an extra coordinator hop and reducing latency.

Question 4

What is the purpose of the `static` column type in a Cassandra table?

Accepted Answer

A column that stores one value per partition shared across all rows in that partition

Answer

Static columns hold a single value per partition key, useful for storing per-partition metadata without duplicating it in every clustering row.

Question 5

Which of the following best describes the role of the snitch in Apache Cassandra?

Accepted Answer

Informs Cassandra about network topology so replicas are placed in different racks or datacenters

Answer

The snitch tells Cassandra about the relative network proximity of nodes, enabling intelligent replica placement across racks and datacenters.

CASSANDRA - Apache Cassandra Database Practice Test