What are the advantages, disadvantages, and limitations of using MySQL triggers?

We must understand the advantages, disadvantages, and limitations of using MySQL triggers in order to use it effectively.

Advantages

The following are the advantages of using MySQL triggers:

• Data integrity -With the help of MySQL triggers processor, we can check the integrity of the data in the table. In other words, MySQL triggers are an alternative way of checking data integrity.
• Capturing Errors -MySQL triggers can capture business logic errors in the database layer.
• Alternative way to run scheduled tasks -In fact, by using MySQL triggers, we do not have to wait for the scheduled tasks to run, because the triggers will update the data in the table Automatically triggered before or after modifications are made.
• Audit -In fact, MySQL triggers are very useful for auditing changes made in tables.
• Preventing invalid transactions -MySQL triggers are very useful in preventing invalid transactions.
• Event logging -MySQL triggers can log events and can also store information about accesses to tables.

Disadvantages

The following are the disadvantages of using MySQL triggers:

• Cannot replace all validations -Actually, MySQL triggers cannot replace all verification and can only provide extended verification.
• Invisible to the client application -Basically, MySQL triggers are invisible when called and executed in the client application, so it is very It's hard to figure out what's going on at the database layer.
• Putting load on the server -Triggers may impose a significant load on the database server.
• Not suitable for high-speed data -Triggers are not suitable for high-speed data, that is, data with a high number of events per second. This is because in the case of high-speed data, the flip-flop will be fired all the time.

Restrictions

The following are some restrictions that apply to MySQL triggers:

• There can only be one trigger per occasion/event -Each table can only have one trigger per opportunity/event combination (that is, we cannot define two BEFORE INSERT triggers for the same table).
• The RETURN statement is not allowed -Since the trigger does not return any value, the RETURN statement is not allowed.
• Foreign key restrictions -Triggers will not be activated by foreign key operations.
• Outdated Metadata - Assuming a trigger is loaded into the cache, it will not automatically reload when the table's metadata changes. In this case, the trigger may operate with outdated metadata.
• Cannot use CALL statement -We cannot use CALL statement in trigger.
• Cannot create a temporary table or view -We cannot create a view for a temporary table or view.
• Will not be activated by changes in INFORMATION_SCHEMA -In fact, the trigger will not be activated by changes in the INFORMATION_SCHEMA or performance_schema tables. This is because these tables are views, and triggers are not allowed on views.

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