In MDM, there are background process which can create the Merge task automatically for the matched records. They can create Merge task manually. However, if the requirement is to create the task automatically, then this sample video can help to understand the process and modify the logic as per their need.
Informatica provides RESOURCEKIT in MDM, under which different sample code is provided for different functionality. Out of these, Customer_task_assignment.sql is also one of them. However, this script has compilation error and it is just an example on the SIP_SAMPLE ORS.
This video elaborate that example which can help to understand how to write the logic under your own ORS.