Cassandra Practice Test

What is the primary benefit of using a two-level index in Cassandra?

1. Reduces data redundancy

2. Aids in more efficient data filtering

3. Improves data retrieval speed

4. Simplifies data replication

The correct answer is: Improves data retrieval speed

The primary benefit of using a two-level index in Cassandra is that it improves data retrieval speed. This indexing strategy divides the index into two levels: a primary index that points to a set of data files and a secondary index that allows for more efficient access to particular data within those files. By having this layered structure, Cassandra can reduce the amount of data that needs to be scanned when executing queries, thus allowing for faster lookups. In a typical scenario without indexing, Cassandra would need to scan through potentially large datasets to find the required information. However, with a two-level index, it significantly minimizes the data that has to be reviewed, leading to quicker retrieval times. This efficiency is especially valuable when dealing with large datasets common in distributed databases like Cassandra, where query performance can greatly affect overall application responsiveness. The other options, while they may have some relevance to performance or data management practices, do not directly relate to the primary advantage of the two-level index. Data redundancy and replication focus more on data integrity and availability, while filtering relates to query performance but does not capture the complete advantage of retrieval speed provided by indexing architecture.