hi, I have a table containinng around 70,000 rows and 2 coloumns. the table is updated every day.(new rows will be added and some rows will be deleted). i need to write a shell script such a way that the difference between yesterdays table and todays table should be written to a new file. the no of rows in yesterdays table and todays table are different.all the rows in yesterday table may or maynot present in todays table i want the out put in such a way that the new file should contain the rows that are present yesterday and changed in any one column in todays table example. file1 aaa,bbb ccc,ddd eee,fff ggg,hhh file2 bbb,rrr ccc,ppp eee,fff kkk,hhh mmm,lll desired output ccc,ddd ccc,ppp ggg,hhh kkk,hhh I tried with comm -3 comand but i am geeting the different rows in two tables as well as new rows in table2 and old rows in table 1. i want only the rows in which there is a change in coloumn value from yesterday table to today table please help me thanks