Cassandra Practice Test

Which of the following is a benefit of compaction?

1. Increased disk usage

2. Less memory pressure

3. Decreased read efficiency

4. Data fragmentation

The correct answer is: Less memory pressure

Compaction in Cassandra is a process that merges SSTables, which are the immutable data files that store your data on disk. One of the primary benefits of compaction is that it helps reduce memory pressure. By consolidating SSTables, compaction minimizes the number of files that need to be managed and read during queries. This reduction in the number of SSTables effectively decreases the memory overhead associated with keeping track of multiple files, leading to more efficient use of system resources and improved performance. When SSTables are compacted, it also helps in optimizing read operations since there are fewer files to read through. This contributes to improved read efficiency in practice, although the correct answer focuses on the specific benefit of less memory usage. Ultimately, managing memory pressure is crucial for ensuring stable performance in a Cassandra environment, especially as the application scales.