What are the pros and cons of using triggers?

The pros and cons of triggers depend on how and why they're applied.

#Pros

1. Automating logic. Triggers run actions without the developer's involvement, logging, recalculating totals, validating data.
2. Guaranteeing data integrity. Even if the application makes a mistake, the trigger still protects the database from invalid changes (e.g. it won't let a customer with active orders get deleted).
3. Centralizing logic. Business rules live right inside the database, so you don't have to duplicate checks in every application that uses that database.
4. Reactivity. They let you implement a "reaction" to changes, e.g. notifications, updating related tables, logging.

#Cons

1. Hidden logic. Table behavior becomes non-obvious, changes happen "behind the scenes", which makes debugging and understanding the code harder.
2. Harder maintenance. With many triggers, it's hard to track the order they fire in and why.
3. Performance issues. Every trigger adds overhead: during bulk operations, they can noticeably slow the system down.
4. Risk of recursion and conflicts. Triggers can call other triggers, creating infinite loops or mutual locks.

Conclusion: Triggers are useful for control and automation inside the database, but overusing them makes the system opaque and heavy. They should be used sparingly, only where the logic genuinely needs to live inside the database itself.