Which statement best describes the impact of inline data compression on performance?

• A. It never affects performance.
• B. It always improves write performance.
• C. It may affect write performance depending on workload.
• D. It eliminates read latency.

Answer: (C)

Inline compression is applied during the write path, so its effect on performance hinges on data compressibility and available CPU resources. If the data compresses well and the CPU has cycles to spare, you end up writing fewer bytes to disk, which reduces I/O and can improve overall write throughput and possibly lower write latency. On the other hand, if the data isn’t very compressible or the system is CPU-bound, the extra work to compress can add latency to writes and reduce throughput. Because of these varying conditions, the best description is that it may affect write performance depending on the workload.