CASSANDRA CQL and Data Modeling 2

Question 1

What is 'ALLOW FILTERING' in CQL and why should it be used with caution?

Accepted Answer

It forces Cassandra to scan all partitions to satisfy a query without a partition key, which is expensive

Answer

It enables full-text search on TEXT columns

Answer

It allows filtering on materialized view columns

Answer

It enables server-side filtering with secondary indexes only

Question 2

What is the purpose of a secondary index in Cassandra?

Accepted Answer

To allow queries on non-primary-key columns without needing ALLOW FILTERING

Answer

To partition data across more nodes

Answer

To compress SSTable files

Answer

To deduplicate rows with the same clustering key

Question 3

In Cassandra data modeling, what is 'denormalization'?

Accepted Answer

Storing duplicate data in multiple tables to support different query patterns efficiently

Answer

Removing duplicate columns from a table

Answer

Normalizing data into separate tables with foreign keys

Answer

Partitioning a large table into smaller ones

Question 4

What does the CQL statement 'UPDATE ... IF EXISTS' provide?

Accepted Answer

A lightweight transaction that only applies the update if the row already exists

Answer

A batch update across multiple partitions

Answer

An upsert that creates the row if missing

Answer

A conditional update using Paxos consensus

Question 5

Which CQL collection type stores an ordered list of elements that allows duplicate values?

Accepted Answer

LIST

Answer

SET

Answer

MAP

Answer

FROZEN

Question 6

What is the maximum recommended size for a Cassandra partition?

Accepted Answer

100 MB

Answer

1 GB

Answer

100 KB

Answer

10 GB