I am writing an SSIS package to run on SQL Server 2008. How do you do an UPSERT in SSIS?
IF KEY NOT EXISTS INSERT ELSE IF DATA CHANGED UPDATE ENDIF ENDI
I usually prefer to let SSIS engine to manage delta merge. Only new items are inserted and changed are updated. If your destination Server does not have enough resources to manage heavy query, this method allow to use resources of your SSIS server.