For some unknown reason I am seeing only the below in the message sent by you. I am replying based on the statement in the subject. ;-)
From the web: On-Line Analytical Processing (OLAP) functions provide the ability to return ranking, row numbering and existing column function information as a scalar value in a query result. An OLAP function can be included in expressions in a select-list or the ORDER BY clause of a select-statement
Statistical functions that will take advantage of Teradata's parallelism, resulting in faster computation of functions such as FORECAST, RANK and QUANTILE; Functions that pre-select data which meet certain criteria and that significantly reduce the amount of data that will need to be returned to intermediate result sets or temporary tables; New "calendar" functions that improve performance of arithmetic and comparisons involving dates.
Please read this elaborate article for better understanding. http://www.dmreview.com/issues/19980901/461-1.html