SQL Rowcount vs Top

Question

What is the difference between

Set Rowcount X

And

Select Top X *
From Z

in TSQL?

Answer 1

2008 and above allows

declare @rc int

set @rc=10000

select top (@rc) * from myTable --will now work

but only if you use () this can be usefull to use hints like:

OPTION ( OPTIMIZE FOR (@rc= 15) )

at the end allowing to select everithing but optimize for a more common case