Thanks for your reply sabrina. Here are your details. I have three input tables of same schema. 1. Table1 ( SELECT DISTINCT A B C D E) 2.Table2( SELECT DISTINCT table2.A ,table2.B ,table2.C, table2.D Table3.E) INNER JOIN Table3 on Table2.A = Table3.A 3.Table4 ( SELECT DISTINCT A B C D E) And using Tunite to merge all these outputs and joining with Table5 on some joining condition and then loading it into Table6 which is in different schema. Note: The volume of data from each table (table1, table2,table4) is high.