A target table can be updated without using \'Update Strategy\'. For this, we need to define the key in the target table in Informatica level and then we need to connect the key and the field we want to update in the mapping Target. In the session level, we should set the target property as \"Update as Update\" and check the \"Update\" check-box.
Let\'s assume we have a target table \"Customer\" with fields as \"Customer ID\", \"Customer Name\" and \"Customer Address\". Suppose we want to update \"Customer Address\" without an Update Strategy. Then we have to define \"Customer ID\" as primary key in Informatica level and we will have to connect Customer ID and Customer Address fields in the mapping. If the session properties are set correctly as described above, then the mapping will only update the customer address field for all matching customer IDs.