Overview

Table 1 lists the aggregate functions supported by DLI.

**Table 1** Aggregate functions
Function	Syntax	Value Type	Description
avg	avg(col), avg(DISTINCT col)	DOUBLE	Returns the average value.
corr	corr(col1, col2)	DOUBLE	Returns the coefficient of correlation of a pair of numeric columns.
count	count([distinct\|all] <colname>)	BIGINT	Returns the number of records.
covar_pop	covar_pop(col1, col2)	DOUBLE	Returns the covariance of a pair of numeric columns.
covar_samp	covar_samp(col1, col2)	DOUBLE	Returns the sample covariance of a pair of numeric columns.
max	max(col)	DOUBLE	Returns the maximum value.
min	min(col)	DOUBLE	Returns the minimum value.
percentile	percentile(BIGINT col, p)	DOUBLE	Returns the percentage value point of the value area. The value of p must be between 0 and 1. Otherwise, NULL is returned. The value cannot be a float.
percentile_approx	percentile_approx(DOUBLE col, p [, B])	DOUBLE	Returns the approximate pth percentile of a numerical column within the group, including floating-point numbers. The value of p should be between 0 and 1. The parameter B controls the accuracy of the approximation, with a higher value of B resulting in a higher level of approximation. The default value is 10000. If the number of non-repeating values in the column is less than B, an exact percentile is returned.
stddev_pop	stddev_pop(col)	DOUBLE	Returns the deviation of a specified column.
stddev_samp	stddev_samp(col)	DOUBLE	Returns the sample deviation of a specified column.
sum	sum(col), sum(DISTINCT col)	DOUBLE	Returns the sum of the values in a column.
variance/var_pop	variance(col), var_pop(col)	DOUBLE	Returns the variance of a column.
var_samp	var_samp(col)	DOUBLE	Returns the sample variance of a specified column.