Cassandra Practice Test

In Cassandra, the default consistency level for reads is indeed set to ONE. This means that when a read request is made, it will return data from the first replica that responds, allowing for the fastest possible read performance. This approach balances speed and availability, ensuring that even if some replicas are down or unreachable, the system will still be able to provide data from at least one available replica.

Choosing ONE as the default consistency level means that the system prioritizes quick responses over the guarantee of the most up-to-date data. This can be particularly useful in distributed systems where network latency might affect response times, allowing applications to continue functioning with at least some level of data access.

While there are higher consistency levels like QUORUM or ANY that provide more stringent guarantees about the accuracy and timeliness of data, these come at the cost of increased read latencies and potentially higher resource usage. ON is a sensible default choice, particularly for applications where availability and speed are critical.