With all the mentioned advantages of the SQL Server triggers, the triggers increase the complexity of the database. If the trigger is badly designed or overused, it will lead to major performance issues, such as blocked sessions, due to extending the life of the transaction for longer time, extra overhead on the system due to executing it each time an INSERT, UPDATE or DELETE action is performed or it may lead to data loss issues. Also, it is not easy to view and trace the database triggers, especially if there is no documentation about it as it is invisible to developers and the applications.
Trigger Alternatives … Enforce Integrity
If it is found that the triggers are harming the performance of your SQL Server instance, you have to replace them with other solutions. For example, rather than using the triggers to enforce the entity integrity, it should be enforced at the lowest level by using the PRIMARY KEY and UNIQUE constraints. The same is applied to the domain integrity that should be enforced through CHECK constraints, and the referential integrity that should be enforced through the FOREIGN KEY constraints. You can use the DML triggers only if the features supported by a specific constraint cannot meet your application requirements.
Trigger Alternatives … Auditing
As we mentioned previously, the triggers can be also used to audit and track the changes performed on a specific table. If this auditing method causes a performance degradation in your SQL Server instance, you can easily replace it with the OUTPUT clause. The OUTPUT clause returns information about each row affected by the INSERT, UPDATE or DELETE operation, in the shape of a confirmation message or a value that can be inserted into the historical table. The OUTPUT clause method provides us also with more control on the executed code, as it will be added to the data insertion, modification or deletion statement itself whenever you want, opposite to the trigger that will be always executed.