By using window functions, for each row from a query, you can perform a calculation using rows related to that row. This is accomplished by using the OVER and WINDOW clauses.
Here is the list of calculations that you can do:
- CUME_DIST(): Cumulative distribution value
- DENSE_RANK(): Rank of the current row within its partition, without gaps
- FIRST_VALUE(): The value of the argument from the first row of the window frame
- LAG(): The argument value from the row lagging the current row within partition
- LAST_VALUE(): Value of argument from the first row of window frame
- LEAD(): Value of argument from row leading current row within partition
- NTH_VALUE(): Argument value from n-th row of window frame
- NTILE(): Bucket number of the current row within its partition
- PERCENT_RANK(): Percentage rank value
- RANK(): Rank of the current row within its partition, with gaps...
