Like FastLoad, MultiLoad does not support Unique Secondary 
Indexes (USIs). But unlike FastLoad, it does support the 
use of Non-Unique Secondary Indexes (NUSIs) because the 
index subtable row is on the same AMP as the data row. 
MultiLoad uses every AMP independently and in parallel. If 
two AMPs must communicate, they are not independent. 
Therefore, a NUSI (same AMP) is fine, but a USI (different 
AMP) is not.

Hi Madhu

Thanks for ur response but could u pls explain ur answer in more detail, if possible with an example?

Thanks again.

When table is having NUSI, the sub table created by it will
be populated only by Hashing (not like Hash Re distribution
for USI), here redistribution of the records will not be
done,which will take more time generally,

As Fastload and Multiload are intended to Load the data at
fast they have taken out the USI, support so that the target
tables will be loaded very faster,

if we need we can create the SI after loading

---
If you have better ANS please Share with us