Windows

For each row in a partition, you can define a sliding window of data. The window determines the range of rows to use for calculations for the current row.

You can base windows on a physical number of rows or a logical interval such as time. Windows have a starting row and an ending row. You can define the window to move at one or both ends. You can define a window to be as large as all the rows in a partition or as small as a sliding window of one row in a partition.