Triggers are used in DBMS to perform a predefined action when a specific event occurs in the database. They are a powerful tool that can be used to enforce data integrity, implement business rules, and automate tasks.

Here are some of the reasons why you might use triggers in DBMS:

• Enforce data integrity: Triggers can be used to enforce data integrity by checking the values of data before they are inserted or updated. For example, you could use a trigger to check that the value of a column is within a certain range.
• Implement business rules: Triggers can be used to implement business rules by taking action when a specific event occurs. For example, you could use a trigger to send an email notification when a new order is placed.
• Automate tasks: Triggers can be used to automate tasks by performing a set of actions when a specific event occurs. For example, you could use a trigger to update a record in another table when a record is inserted or updated in the current table.

Triggers can be a powerful tool for managing your database. By using triggers, you can enforce data integrity, implement business rules, and automate tasks.

Here are some of the advantages of using triggers:

• Enforce data integrity: Triggers can be used to enforce data integrity by checking the values of data before they are inserted or updated. This can help to prevent errors and ensure that the data in your database is accurate and consistent.
• Implement business rules: Triggers can be used to implement business rules by taking action when a specific event occurs. This can help to automate tasks and ensure that your database is always in a consistent state.
• Automate tasks: Triggers can be used to automate tasks by performing a set of actions when a specific event occurs. This can save time and effort by eliminating the need to manually perform these tasks.

Here are some of the disadvantages of using triggers:

• Performance: Triggers can impact the performance of your database. This is because triggers are executed every time a specific event occurs. If you have a lot of triggers, or if they are complex, they can slow down your database.
• Complexity: Triggers can be complex to write and maintain. This is because they need to be written in a programming language, such as SQL. If you are not familiar with programming, you may find it difficult to write and maintain triggers.
• Security: Triggers can be a security risk. This is because they can be used to access and modify data in your database. If a malicious user is able to gain access to your triggers, they could use them to steal or modify your data.

Overall, triggers are a powerful tool that can be used to manage your database. However, they can also impact the performance and security of your database. It is important to weigh the pros and cons of using triggers before deciding whether or not to use them.

In a DBMS, a trigger is a SQL procedure that initiates an action when an DML operation (INSERT, DELETE or UPDATE) occurs. So we can say that triggers are event-driven specialized procedures, they are stored in and managed by the DBMS.

A trigger cannot be called or executed; the DBMS automatically fires the trigger as a result of a data modification to the associated table. Triggers are used to maintain the referential integrity of data by changing the data in a systematic fashion.