Lets assume we have a table as follows:
PK -- nonclustered primary key Col1 -- unique clustered Col2 Col3
Is this index:
nonclustered index on (Col2, Col3)
any different from this index:
nonclustered index on (Col2, Col3) include (PK)
What if my PK is clustered instead of nonclustered? Now does it make/not make a difference?
Edit to add:
I suppose this is a round-about way of asking: Is the nonclustered index's pointer back to the table based on the clustered index or the primary key? I assume the clustered index RID is what is used.