>Michael, would you care to explain to me what is and the diff.
>between NC(non-cluster) indexes and cluster indexes. Thanks.

First, understand that a SQL Server index is structured like a tree. A clustered index has two very important properties. First, the leaf level of the index is actually the data. The index sits on top of the table. This causes the second important property - the table is physically sorted based on the clustered index key. And this sorting is maintained by the server. Because of this, you can only have one clustered index.

Root - Internal Nodes - Leaf (table data pages)


Non-clutered indexes have a leaf level that is seperate from the table. At the leaf level, all keys contain a ptr to the the row within the table.

Root - Internal Nodes - Leaf - Table data pages


-Mike