Cassandra Practice Test

Which of the following statements about partitioning in Cassandra is true?

1. Partitions can have unlimited size without performance issues

2. Small partitions are always the best choice

3. Large partitions can lead to degraded performance

4. Partitions should be sized according to user preferences

The correct answer is: Large partitions can lead to degraded performance

The statement regarding large partitions leading to degraded performance is accurate because, in Cassandra, partitions that are excessively large can create several operational challenges. Large partitions may take longer to read or write due to the increased amount of data handled in a single unit. When partitions grow too large, they can also impact garbage collection, cause longer compaction times, and affect the performance during query execution, leading to timeouts or resource contention. Cassandra is designed to work effectively with a balanced partition size to ensure efficient data access patterns. It generally favors partitions that cover up to a few megabytes in size, allowing for manageable reads and writes. Keeping partitions within an optimal range prevents performance bottlenecks and enhances the overall responsiveness of the system. In contrast, very small partitions can lead to an increased number of partitions, which could also have adverse effects, but they do not inherently degrade performance the way overly large partitions do.