CELKO (7/18/2011)
SIGN (1 + SIGN(x)) * xbut it means using x twice. Hide it in a CTE and use the twice.
CTEs generally don't help - the expression is evaluated twice.
I included the TOP trick as the only way I know to force the query processor to evaluate just once.
Paul White
SQLPerformance.com
SQLkiwi blog
@SQL_Kiwi