How does the HANA database handle invalid transactions?

The HANA database handles invalid transactions primarily by employing rollback mechanisms to ensure data integrity. This approach is critical in a database environment where maintaining the consistency and reliability of data is paramount. When a transaction encounters an error or becomes invalid, the rollback mechanism allows the database to revert to its last stable state before the transaction began. This ensures that any partial changes made by the invalid transaction are not committed, thus preserving the overall integrity of the database.

Rollback mechanisms are essential in a transactional database because they provide a way to recover from errors without manual intervention. This is especially important in environments where data accuracy is critical, such as financial applications or customer relationship management systems. By effectively supporting these rollback operations, HANA can confidently manage concurrent transactions while ensuring that one invalid transaction does not compromise the entire system.

Other options like marking transactions as read-only, permanently deleting invalid transactions, and sending alerts to system administrators are not primary methods for handling invalid transactions in HANA. Such alternatives do not preserve data integrity in the same way that rollback mechanisms do, thereby reducing their applicability in robust transactional management.