Aggregate Functions¶
Aggregate functions operate on a set of values to compute a single result.
General¶
avg¶
Returns the average of numeric values in the specified column.
avg(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
Aliases¶
mean
bit_and¶
Computes the bitwise AND of all non-null input values.
bit_and(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
bit_or¶
Computes the bitwise OR of all non-null input values.
bit_or(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
bit_xor¶
Computes the bitwise exclusive OR of all non-null input values.
bit_xor(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
bool_and¶
Returns true if all non-null input values are true, otherwise false.
bool_and(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
bool_or¶
Returns true if any non-null input value is true, otherwise false.
bool_or(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
count¶
Returns the number of rows in the specified column.
Count includes null values in the total count.
To exclude null values from the total count, include <column> IS NOT NULL
in the WHERE clause.
count(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
max¶
Returns the maximum value in the specified column.
max(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
mean¶
Alias of avg.
median¶
Returns the median value in the specified column.
median(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
min¶
Returns the minimum value in the specified column.
min(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
sum¶
Returns the sum of all values in the specified column.
sum(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
array_agg¶
Returns an array created from the expression elements. If ordering requirement is given, elements are inserted in the order of required ordering.
array_agg(expression [ORDER BY expression])
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
first_value¶
Returns the first element in an aggregation group according to the requested ordering. If no ordering is given, returns an arbitrary element from the group.
first_value(expression [ORDER BY expression])
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
last_value¶
Returns the last element in an aggregation group according to the requested ordering. If no ordering is given, returns an arbitrary element from the group.
last_value(expression [ORDER BY expression])
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
Statistical¶
corr¶
Returns the coefficient of correlation between two numeric values.
corr(expression1, expression2)
Arguments¶
expression1: First expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
expression2: Second expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
covar¶
Returns the covariance of a set of number pairs.
covar(expression1, expression2)
Arguments¶
expression1: First expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
expression2: Second expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
covar_pop¶
Returns the population covariance of a set of number pairs.
covar_pop(expression1, expression2)
Arguments¶
expression1: First expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
expression2: Second expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
covar_samp¶
Returns the sample covariance of a set of number pairs.
covar_samp(expression1, expression2)
Arguments¶
expression1: First expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
expression2: Second expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
stddev¶
Returns the standard deviation of a set of numbers.
stddev(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
stddev_pop¶
Returns the population standard deviation of a set of numbers.
stddev_pop(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
stddev_samp¶
Returns the sample standard deviation of a set of numbers.
stddev_samp(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
var¶
Returns the statistical variance of a set of numbers.
var(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
var_pop¶
Returns the statistical population variance of a set of numbers.
var_pop(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
var_samp¶
Returns the statistical sample variance of a set of numbers.
var_samp(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
regr_slope¶
Returns the slope of the linear regression line for non-null pairs in aggregate columns. Given input column Y and X: regr_slope(Y, X) returns the slope (k in Y = k*X + b) using minimal RSS fitting.
regr_slope(expression1, expression2)
Arguments¶
expression_y: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
expression_x: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
regr_avgx¶
Computes the average of the independent variable (input) expression_x for the non-null paired data points.
regr_avgx(expression_y, expression_x)
Arguments¶
expression_y: Dependent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
expression_x: Independent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
regr_avgy¶
Computes the average of the dependent variable (output) expression_y for the non-null paired data points.
regr_avgy(expression_y, expression_x)
Arguments¶
expression_y: Dependent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
expression_x: Independent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
regr_count¶
Counts the number of non-null paired data points.
regr_count(expression_y, expression_x)
Arguments¶
expression_y: Dependent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
expression_x: Independent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
regr_intercept¶
Computes the y-intercept of the linear regression line. For the equation (y = kx + b), this function returns b.
regr_intercept(expression_y, expression_x)
Arguments¶
expression_y: Dependent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
expression_x: Independent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
regr_r2¶
Computes the square of the correlation coefficient between the independent and dependent variables.
regr_r2(expression_y, expression_x)
Arguments¶
expression_y: Dependent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
expression_x: Independent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
regr_sxx¶
Computes the sum of squares of the independent variable.
regr_sxx(expression_y, expression_x)
Arguments¶
expression_y: Dependent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
expression_x: Independent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
regr_syy¶
Computes the sum of squares of the dependent variable.
regr_syy(expression_y, expression_x)
Arguments¶
expression_y: Dependent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
expression_x: Independent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
regr_sxy¶
Computes the sum of products of paired data points.
regr_sxy(expression_y, expression_x)
Arguments¶
expression_y: Dependent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
expression_x: Independent variable. Can be a constant, column, or function, and any combination of arithmetic operators.
Approximate¶
approx_distinct¶
Returns the approximate number of distinct input values calculated using the HyperLogLog algorithm.
approx_distinct(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
approx_median¶
Returns the approximate median (50th percentile) of input values.
It is an alias of approx_percentile_cont(x, 0.5).
approx_median(expression)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
approx_percentile_cont¶
Returns the approximate percentile of input values using the t-digest algorithm.
approx_percentile_cont(expression, percentile, centroids)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
percentile: Percentile to compute. Must be a float value between 0 and 1 (inclusive).
centroids: Number of centroids to use in the t-digest algorithm. Default is 100.
If there are this number or fewer unique values, you can expect an exact result. A higher number of centroids results in a more accurate approximation, but requires more memory to compute.
approx_percentile_cont_with_weight¶
Returns the weighted approximate percentile of input values using the t-digest algorithm.
approx_percentile_cont_with_weight(expression, weight, percentile)
Arguments¶
expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
weight: Expression to use as weight. Can be a constant, column, or function, and any combination of arithmetic operators.
percentile: Percentile to compute. Must be a float value between 0 and 1 (inclusive).