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
GROUP_CONCAT concatenated string of a column