Cassandra Practice Test

What negative effect can occur if partition sizes exceed the recommended limits in Cassandra?

1. Increased write latency

2. Higher storage costs

3. Data corruption

4. Lower query performance

The correct answer is: Lower query performance

When partition sizes exceed the recommended limits in Cassandra, one significant negative effect is lower query performance. This issue arises because larger partitions can lead to inefficient data retrieval. In Cassandra, each partition is designed to fit within memory for optimal performance. When a partition grows too large, it may result in increased read times as more data needs to be scanned and processed. On the other hand, queries against excessively large partitions may trigger additional disk I/O operations, leading to slower performance. Each query requires scanning the data in the partition to fetch the requested information. As partition size grows, this scanning process can take significantly longer, leading to a noticeable degradation in performance for read operations. While increased write latency, higher storage costs, and data corruption are potential concerns in other contexts, the primary impact concerning query performance is more direct and observable, making it a critical issue to manage in Cassandra data modeling. Proper partitioning strategies help prevent these performance drops, ensuring efficient queries even as data volume scales.