Window functions

Rank rows and read values from neighbouring rows within a window. Aggregate functions can also run over windows.

Function	Type	What it does
`cume_dist`	Window	Returns the fraction of rows in the group that come before or tie with the current row in the specified order.
`dense_rank`	Window	Returns consecutive ranks without gaps for equal ordering values.
`lag`	Window	Returns a value from an earlier row in the same group defined by PARTITION BY.
`lead`	Window	Returns a value from a later row in the same group defined by PARTITION BY.
`ntile`	Window	Divides the ordered rows in each group into buckets as evenly as possible.
`rank`	Window	Returns ranks with gaps after equal ordering values.
`row_number`	Window	Assigns consecutive row numbers starting at 1 within each group defined by PARTITION BY.

Last modified on October 15, 2026