Siddaramaiah took oath as the chief minister of Karnataka while state Congress president DK Shivakumar was sworn-in as the deputy chief minister on Saturday, a week after the grand old party secured a decisive victory in the assembly elections.Siddaramaiah, who had earlier served as the chief minister of Karnataka from 2013 to 2018, emerged as the Congress pick for the top post after a hectic tussle with Shivakumar that lasted nearly one week.