SQL Server Windows function

SQL Server Window Functions calculate an aggregate value based on a group of rows and return multiple rows for each group.

Name	Description
CUME_DIST	Calculate the cumulative distribution of a value in a set of values
DENSE_RANK	Assign a rank value to each row within a partition of a result, with no gaps in rank values.
FIRST_VALUE	Get the value of the first row in an ordered partition of a result set.
LAG	Provide access to a row at a given physical offset that comes before the current row.
LAST_VALUE	Get the value of the last row in an ordered partition of a result set.
LEAD	Provide access to a row at a given physical offset that follows the current row.
NTILE	Distribute rows of an ordered partition into a number of groups or buckets
PERCENT_RANK	Calculate the percent rank of a value in a set of values.