Windowing

Windowing is used to smooth out random variations.

It can be used to calculate moving averages.

select date, sum(value) over
(order by date between rows 1 preceding and 1 following)
from sales

Examples of other window specifications:

• between rows unbounded preceding and current

• rows unbounded preceding

• range between 10 preceding and current row

  • all rows with values between current row value –10 to current value

• range interval 10 day preceding

  • not including current row