# percentile()

`percentile(n, col)`

returns the `n`

-th percentile value of the provided column in the input datastream. A value at the `n`

-th percentile means that `n`

% of the values in the input datastream are below that value.

`n`

must be a numeric value between 0 and 100. Floating point numbers are accepted.

If the provided column does not have numeric values or does not exist, `percentile`

will return `null`

; otherwise, `percentile`

will always return a value that was part of the input datastream.

## Technical Notes

If there are at most 1000 values in the input stream,

`percentile`

uses the nearest rank algorithm to return the exact value.If there are more than 1000 values in the input stream,

`percentile`

uses the Karnin, Lang, and Liberty (KLL) algorithm to return an approximation. The approximation is generally within 1% rank error, e.g. the value returned for the 90th percentile will usually be between the 89th and 91st percentile.

## Returns

A table with one row and one column, called `@q.value`

.

## Examples

Last updated