In what cases can caching lead to negative consequences or reduce system efficiency?

Caching can lead to negative consequences or reduce system efficiency in the following cases:

• Stale data: if the cache is not updated in a timely manner, the application may work with incorrect or outdated information.
• Excessive memory consumption: a cache that is too large can occupy a lot of RAM, leading to decreased performance due to frequent garbage collection or swapping.
• Support complexity: improper cache management (e.g., lack of invalidation policy) complicates application logic and can lead to errors.
• Low likelihood of data reuse: if data is rarely reused, caching will not provide a benefit and will only add overhead.
• High cost of cache updates: if updating the cache requires significant resources, it can degrade overall performance.

Example: in a web application where data changes frequently, aggressive caching without a proper update mechanism can lead to users seeing outdated information.