Hey pradyumna,
why a table is permitted have only one primary key or unique key
or
why only one unique cluster index is allowed on a table
Answer :
1st : A Table can have more than one unique constraints .
2nd : Clustered index is maximum one per table because of clustered index orders the data in the table based on the definition of that table.
Hope you it will work for you.
Cheers!
Sandy.
--