Below is the list of Aggregate Function that BigObject supports:

Aggregation Function Return Value
SUM sum of a numeric column
COUNT number of rows
COUNT (DISTINCT) the count of different values of a column
APPROXIMATE COUNT (DISTINCT) the approximate count of different values of a column
MAX maximum of a numeric column
MIN minimum of a numeric column
AVG average of a numeric column
STD (population) standard deviation of a numeric column
STDDEV_SAMP sample standard deviation of a numeric column
STDDEV_POP population standard deviation of a numeric column
VARIANCE (population) variance of a numeric column
VAR_SAMP sample variance of a numeric column
VAR_POP population variance of a numeric column
NORM percentage of sum of a numeric column
CORR correlation between two numeric columns