-- continuous uniform distribution has kurtosis = -6/5, skewness = 0.0 -- http://mathworld.wolfram.com/UniformDistribution.html set client_min_messages to ERROR; With dist As ( SELECT random()::numeric As val FROM generate_series(1,50000) t ) SELECT -- does random dist values match within 1% of known values abs(CDB_Kurtosis(array_agg(val)) + 1.20) < 1e-2 As kurtosis, abs(CDB_Skewness(array_agg(val)) - 0) < 1e-2 As skewness FROM dist; set client_min_messages to NOTICE;