What are the drawbacks of MyBatis second-level cache?

Disadvantages of MyBatis second-level cache include:

1. Data inconsistency: Updating the same data in multiple sessions can result in discrepancies between the data in the cache and the database.
2. Memory Usage: The secondary cache stores query results in memory, and if there is a large amount of cached data, it will consume a significant amount of memory.
3. Expiration issues with caches: Data in the secondary cache may become invalid due to the passage of time or other reasons, leading to inaccurate query results.
4. Challenges in a distributed environment: In a distributed environment, the secondary cache between different application instances is independent, which may lead to issues of data inconsistency.
5. Object-Relational Mapping (ORM) Issue: MyBatis operates data using object-relational mapping (ORM), but the second-level cache can only cache query results, not object relationships.
6. Cache penetration issue: If a query request’s result is not found in the database, then every request will penetrate the cache, causing the cache to become invalid.
7. Issue with object updates: If the corresponding data in the cache is not properly cleared when updating an object, it may result in retrieving outdated data.