I am writing a scheduled federated query to load my BiqQuery tables on a daily basis. BigQuery table load strategy is Overwrite. My source is a Cloud SQL database (mysql instance).
I am wondering what would be the correct approach from a performance and cost-optimization perspective in the long run to load my BigQuery tables? Should I overwrite my BigQuery tables daily with source data or should I build a logic in my federated query itself using joins to detect just the new additions in source and then add them to my BigQuery table during daily scheduled runs?