Explain plan for set table - response (6) by abin

Thanks all for the responses.
 
Vlad,
Yes the statment has a spello, it should read as " I did an explain plan on insert statmenets for a table defined as set and then altered it as multiset."
 
Raja,
The volume of data differes, I have around 60 tables to consider.
 
So all in all , I am going to look at the data volume I am expecting on each table. If table volume is not expected to be less even after long period, I am planning to keep them as set.
For larger tables (in count), I will have to check the trade off between keeping table as set and doing a group by on all fields after changing table to multiset. This is where I am stuck, because adddition of group by shows in plan with additional time and I am not able to check if that extra time is bad or good than the AMP level duplicate check for set table.
 
Abin.