Is there any attribute a customer can set in the API call to extract the desired columns data in the results?

In regard to extract only certain columns you need, you can use the "Select" statement in the API Call URL where you can add the desired fields name for extracting only certain columns you need. 
 
For example: 
1) Event_details :  
URL: https://api.resilinc.com/v1/event_details?select=id 
Result: As per the select statement, only Ids in ascending order will be retrieved. 
  
 
 

2) Partner_events :  
URL: https://api.resilinc.com/v1/partner_events?select=partner_id, event_id 
Result: As per select statement, only partner_id, event_id in ascending order will be retrieved.