You have created an External Table(E_Prev_MPI) in which you have loaded all the Historical data from an MPI source system, you need to join the E_Prev_MPI table with one of the tables in Warehouse (W_Curr_MPI) which has the current snapshot of data, and if there are any matching records, you need to update the E_Prev_MPI.Matched column to 'Yes' There are a lot of performance issues while performing the update so you have created Partition on the E_Prev_MPI table. Is this the best approach?