quantile.sql_in File Reference

SQL function for Quantile. More...

Functions
float	quantile_big (text table_name, text col_name, float quantile)
	Computes quantile. More...
float	quantile (text table_name, text col_name, float quantile)
	Computes quantile. More...

Detailed Description

Date

January 2011

See also

For a brief introduction to quantiles, see the module description Quantile.

Function Documentation

float quantile	(	text	table_name,
		text	col_name,
		float	quantile
	)

Parameters

table_name	name of the table from which quantile is to be taken
col_name	name of the column that is to be used for quantile calculation
quantile	desired quantile value \( \in (0,1) \)

Returns

The quantile value

This function computes the specified quantile value. It reads the name of the table, the specific column, and computes the quantile value based on the fraction specified as the third argument.

float quantile_big	(	text	table_name,
		text	col_name,
		float	quantile
	)

Parameters

table_name	name of the table from which quantile is to be taken
col_name	name of the column that is to be used for quantile calculation
quantile	desired quantile value \( \in (0,1) \)

Returns

The quantile value

This function computes the specified quantile value. It reads the name of the table, the specific column, and computes the quantile value based on the fraction specified as the third argument. The functionality is the same as quantile except this implementation is designed to work more efficiently with large tables.