| 返回類型 | 函數 | 說明 | bigint | count(*) , count(expr), count(DISTINCT expr[, expr_., expr_.]) | 返回記錄條數。 | double | sum(col), sum(DISTINCT col) | 求和 | double | avg(col), avg(DISTINCT col) | 求平均值 | double | min(col) | 返回指定列中最小值 | double | max(col) | 返回指定列中最大值 | double | var_pop(col) | 返回指定列的方差 | double | var_samp(col) | 返回指定列的樣本方差 | double | stddev_pop(col) | 返回指定列的偏差 | double | stddev_samp(col) | 返回指定列的樣本偏差 | double | covar_pop(col1, col2) | 兩列數值協方差 | double | covar_samp(col1, col2) | 兩列數值樣本協方差 | double | corr(col1, col2) | 返回兩列數值的相關係數 | double | percentile(col, p) | 返回數值區域的百分比數值點。0<=P<=1,否則返回NULL,不支持浮點型數值。 | array<double> | percentile(col, array(p~1,,\ [, p,,2,,]…)) | 返回數值區域的一組百分比值分別對應的數值點。0<=P<=1,否則返回NULL,不支持浮點型數值。 | double | percentile_approx(col, p[, B]) | Returns an approximate p^th^ percentile of a numeric column (including floating point types) in the group. The B parameter controls approximation accuracy at the cost of memory. Higher values yield better approximations, and the default is 10,000. When the number of distinct values in col is smaller than B, this gives an exact percentile value. | array<double> | percentile_approx(col, array(p~1,, [, p,,2_]…) [, B]) | Same as above, but accepts and returns an array of percentile values instead of a single one. | array<struct\{‘x’,'y’\}> | histogram_numeric(col, b) | Computes a histogram of a numeric column in the group using b non-uniformly spaced bins. The output is an array of size b of double-valued (x,y) coordinates that represent the bin centers and heights | array | collect_set(col) | 返回無重複記錄 |
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