Scheduler task: On a periodic basis a service will be executed. Scheduler task details would be stored in database. Could be in product schema. I would like to know the table name where in the IS retrieving the info to run the scheduler.
System task: Integration Server will create a system task on his own for internal purpose.
Question here is will the system task details also would be stored in database or it would be store in cache?
How exactly Integration server handle the situation?
The schedulers are stored in the table IS_USER_TASKS in the IS-Internal section.
I am not sure if the system tasks are stored too.
There is a thread in the IS-Thread list dealing with the schedulers and starting the appropriate actions when they are due.
Regards,
Holger
I agree with Holger above 
As per SAG docs, System tasks are not stored in the database!!!
System tasks are in-memory only. They are created by Integration Server during initialization. Note that one implication of this is that system tasks, unlike user tasks, cannot be shared by nodes in a cluster.
Regards,
Michael