LOG() function has been enhanced in SQL Server 2012 for accepting base value as second argument...
LOG() function used to accept logarithmic value of any base. It accepts base value as second parameter. In SQL Server 2008, LOG() function doesn't accept second argument.Syntax of LOG() in MSSQL 2012
LOG ( float_expression[, base] )
SELECT LOG(10) as Log10 Output
,LOG(9,3) as Log10Base3
,LOG(10)/LOG(2) as Log10DivideByLog2
Log10 Log10Base3 Log10Base2 Log10DivideByLog2
2.30258509299405 2 3.32192809488736 3.32192809488736