Suvendu (2/15/2011)
A clustered index is a special type of index that reorders the way records in the table are physically stored.
The clustered index enforces the logical storage order of the actual rows of the table, not the physical order. SQL will try, on create or rebuild, to make the two as similar as possible, but it is unlikely that they will remain that way
A nonclustered index is a special type of index in which the logical order of the index does not match the physical stored order of the rows on disk.
A nonclustered index is a separate structure from the table, the nonclustered index key enforces the logical order of the index rows, not the physical order.
p.s. this thread is 4 years old.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability