covar_sampcovar_samp covar_samp介绍 covar_samp(expr1, expr2) - 返回一组数字对的样本协方差。 Examples: > SELECT covar_samp(c1, c2) FROM VALUES (1,1), (2,2), (3,3) AS tab(c1, c2); 1.0 Since: 2.0.0covar_popcrc32