34 KiB
title | list_title | description | menu | weight | related | |||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
SQL aggregate functions | Aggregate functions | Aggregate data with SQL aggregate functions. |
|
301 |
|
SQL aggregate functions aggregate values in a specified column for each group or SQL partition and return a single row per group containing the aggregate value.
General aggregate functions
- array_agg
- avg
- bit_and
- bit_or
- bit_xor
- bool_and
- bool_or
- count
- first_value
- last_value
- max
- mean
- median
- min
- sum
array_agg
Returns an array created from the expression elements.
{{% note %}}
array_agg
returns a LIST
arrow type which is not supported by InfluxDB.
To use with InfluxDB, use bracket notation to reference the index of an element
in the returned array. Arrays are 1-indexed.
{{% /note %}}
array_agg(expression)
Arguments
- expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
{{< expand-wrapper >}}
{{% expand "View array_agg
query example" %}}
The following example uses the sample data set provided in the Get started with InfluxDB tutorial.
SELECT
room,
array_agg(temp)[3] AS '3rd_temp'
FROM home
GROUP BY room
room | 3rd_temp |
---|---|
Kitchen | 22.7 |
Living Room | 21.8 |
{{% /expand %}} {{< /expand-wrapper >}}
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
{{< expand-wrapper >}}
{{% expand "View avg
query example" %}}
SELECT
location,
avg(water_level) AS water_level_avg
FROM h2o_feet
GROUP BY location
location | water_level_avg |
---|---|
coyote_creek | 5.359142420303919 |
santa_monica | 3.5307120942458843 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View bit_and
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
bit_and(precip::BIGINT) AS precip_bit_and
FROM weather
GROUP BY location
location | precip_bit_and |
---|---|
Concord | 0 |
Hayward | 0 |
San Francisco | 0 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View bit_or
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
bit_or(precip::BIGINT) AS precip_bit_or
FROM weather
GROUP BY location
location | precip_bit_or |
---|---|
Concord | 7 |
Hayward | 7 |
San Francisco | 7 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View bit_xor
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
bit_xor(precip::BIGINT) AS precip_bit_xor
FROM weather
GROUP BY location
location | precip_bit_xor |
---|---|
Concord | 4 |
Hayward | 6 |
San Francisco | 4 |
{{% /expand %}} {{< /expand-wrapper >}}
bool_and
Returns true
if all non-null input values are true
, otherwise returns false
.
bool_and(expression)
Arguments
- expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
{{< expand-wrapper >}}
{{% expand "View bool_and
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
bool_and(precip > 0) AS precip_bool_and
FROM weather
GROUP BY location
location | precip_bool_and |
---|---|
Concord | false |
Hayward | false |
San Francisco | false |
{{% /expand %}} {{< /expand-wrapper >}}
bool_or
Returns true
if any non-null input value is true
, otherwise returns false
.
bool_or(expression)
Arguments
- expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
{{< expand-wrapper >}}
{{% expand "View bool_or
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
bool_or(precip > 0) AS precip_bool_or
FROM weather
GROUP BY location
location | precip_bool_or |
---|---|
Concord | true |
Hayward | true |
San Francisco | true |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View count
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
count(precip) AS precip_count
FROM weather
GROUP BY location
location | precip_count |
---|---|
Concord | 1094 |
Hayward | 1096 |
San Francisco | 1096 |
{{% /expand %}} {{< /expand-wrapper >}}
first_value
Returns the first element in an aggregation group according to the specified ordering. If no ordering is specified, 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.
{{< expand-wrapper >}}
{{% expand "View first_value
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
first_value(temp_max ORDER BY time) AS temp_max_first_value
FROM weather
GROUP BY location
location | temp_max_first_value |
---|---|
Concord | 59 |
Hayward | 57 |
San Francisco | 66 |
{{% /expand %}} {{< /expand-wrapper >}}
last_value
Returns the last element in an aggregation group according to the specified ordering. If no ordering is specified, 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.
{{< expand-wrapper >}}
{{% expand "View last_value
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
last_value(temp_max ORDER BY time) AS temp_max_last_value
FROM weather
GROUP BY location
location | temp_max_last_value |
---|---|
Concord | 59 |
Hayward | 58 |
San Francisco | 62 |
{{% /expand %}} {{< /expand-wrapper >}}
max
Returns the maximum value in the specified column.
max(expression)
To return both the maximum value and its associated timestamp, use
selector_max
.
Arguments
- expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
{{< expand-wrapper >}}
{{% expand "View max
query example" %}}
SELECT
location,
max(water_level) AS water_level_max
FROM h2o_feet
GROUP BY location
location | water_level_max |
---|---|
santa_monica | 7.205 |
coyote_creek | 9.964 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View median
query example" %}}
SELECT
location,
median(water_level) AS water_level_max
FROM h2o_feet
GROUP BY location
location | water_level_median |
---|---|
coyote_creek | 5.4645 |
santa_monica | 3.471 |
{{% /expand %}} {{< /expand-wrapper >}}
min
Returns the minimum value in the specified column.
min(expression)
To return both the minimum value and its associated timestamp, use
selector_max
.
Arguments
- expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
{{< expand-wrapper >}}
{{% expand "View min
query example" %}}
SELECT
location,
min(water_level) AS water_level_min
FROM h2o_feet
GROUP BY location
location | water_level_min |
---|---|
coyote_creek | -0.61 |
santa_monica | -0.243 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View sum
query example" %}}
SELECT
location,
sum(water_level) AS water_level_sum
FROM h2o_feet
GROUP BY location
location | water_level_sum |
---|---|
santa_monica | 27024.070369358 |
coyote_creek | 40750.918963991004 |
{{% /expand %}} {{< /expand-wrapper >}}
Statistical aggregate functions
- corr
- covar
- covar_pop
- covar_samp
- regr_avgx
- regr_avgy
- regr_count
- regr_intercept
- regr_r2
- regr_slope
- regr_sxx
- regr_syy
- regr_sxy
- stddev
- stddev_pop
- stddev_samp
- var
- var_pop
- var_samp
corr
Returns the coefficient of correlation between two numeric values.
corr(expression1, expression2)
Arguments
- expression1: First column or literal value to operate on.
- expression2: Second column or literal value to operate on.
{{< expand-wrapper >}}
{{% expand "View corr
query example" %}}
The following example uses the sample data set provided in Get started with InfluxDB tutorial.
SELECT
room,
corr(hum, temp) AS correlation
FROM home
GROUP BY room
room | correlation |
---|---|
Living Room | 0.43665270457835725 |
Kitchen | 0.6741766954929539 |
{{% /expand %}} {{< /expand-wrapper >}}
covar
Returns the covariance of a set of number pairs.
covar(expression1, expression2)
Arguments
- expression1: First column or literal value to operate on.
- expression2: Second column or literal value to operate on.
{{< expand-wrapper >}}
{{% expand "View covar
query example" %}}
The following example uses the sample data set provided in Get started with InfluxDB tutorial.
SELECT
room,
covar(hum, temp) AS covar
FROM home
GROUP BY room
room | covar |
---|---|
Living Room | 0.03346153846153959 |
Kitchen | 0.11134615384615432 |
{{% /expand %}} {{< /expand-wrapper >}}
covar_pop
Returns the population covariance of a set of number pairs.
covar_pop(expression1, expression2)
Arguments
- expression1: First column or literal value to operate on.
- expression2: Second column or literal value to operate on.
{{< expand-wrapper >}}
{{% expand "View covar_pop
query example" %}}
The following example uses the sample data set provided in Get started with InfluxDB tutorial.
SELECT
room,
covar_pop(hum, temp) AS covar_pop
FROM home
GROUP BY room
room | covar_pop |
---|---|
Kitchen | 0.10278106508875783 |
Living Room | 0.030887573964498087 |
{{% /expand %}} {{< /expand-wrapper >}}
covar_samp
Returns the sample covariance of a set of number pairs.
covar_samp(expression1, expression2)
Arguments
- expression1: First column or literal value to operate on.
- expression2: Second column or literal value to operate on.
{{< expand-wrapper >}}
{{% expand "View covar_samp
query example" %}}
The following example uses the sample data set provided in Get started with InfluxDB tutorial.
SELECT
room,
covar_samp(hum, temp) AS covar_samp
FROM home
GROUP BY room
room | covar_samp |
---|---|
Kitchen | 0.11134615384615432 |
Living Room | 0.03346153846153959 |
{{% /expand %}} {{< /expand-wrapper >}}
regr_avgx
Computes the average of the independent variable (input), expression_x
, for the
non-null dependent variable, expression_y
.
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.
{{< expand-wrapper >}}
{{% expand "View regr_avgx
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
regr_avgx(temp_min, temp_max) AS temp_regr_avgx
FROM weather
GROUP BY location
location | temp_regr_avgx |
---|---|
Concord | 75.54379562043796 |
Hayward | 69.14808043875686 |
San Francisco | 67.59945255474454 |
{{% /expand %}} {{< /expand-wrapper >}}
regr_avgy
Computes the average of the dependent variable (output), expression_y
, for the
non-null dependent variable, expression_y
.
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.
{{< expand-wrapper >}}
{{% expand "View regr_avgy
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
regr_avgy(temp_min, temp_max) AS temp_regr_avgy
FROM weather
GROUP BY location
location | temp_regr_avgy |
---|---|
Concord | 50.153284671532845 |
Hayward | 50.913162705667276 |
San Francisco | 51.52372262773722 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View regr_count
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
regr_count(temp_min, temp_max) AS temp_regr_count
FROM weather
GROUP BY location
location | temp_regr_count |
---|---|
Concord | 1096 |
Hayward | 1094 |
San Francisco | 1096 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View regr_intercept
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
regr_intercept(temp_min, temp_max) AS temp_regr_intercept
FROM weather
GROUP BY location
location | temp_regr_intercept |
---|---|
Concord | 11.636281392206769 |
Hayward | 12.876956842745152 |
San Francisco | 19.125237647086607 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View regr_r2
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
regr_r2(temp_min, temp_max) AS temp_regr_r2
FROM weather
GROUP BY location
location | temp_regr_r2 |
---|---|
Concord | 0.6474628308450441 |
Hayward | 0.5166296626320914 |
San Francisco | 0.5032317511200297 |
{{% /expand %}} {{< /expand-wrapper >}}
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(expression_y, expression_x)
Arguments
- expression_y: Y expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
- expression_x: X expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
{{< expand-wrapper >}}
{{% expand "View regr_slope
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
regr_slope(temp_min, temp_max) AS temp_regr_slope
FROM weather
GROUP BY location
location | temp_regr_slope |
---|---|
Concord | 0.5098632252058237 |
Hayward | 0.5500688612261629 |
San Francisco | 0.4792714105844738 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View regr_sxx
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
regr_sxx(temp_min, temp_max) AS temp_regr_sxx
FROM weather
GROUP BY location
location | temp_regr_sxx |
---|---|
Concord | 210751.89781021897 |
Hayward | 99644.01096892142 |
San Francisco | 77413.15967153282 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View regr_syy
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
regr_syy(temp_min, temp_max) AS temp_regr_syy
FROM weather
GROUP BY location
location | temp_regr_syy |
---|---|
Concord | 84618.24817518248 |
Hayward | 58358.750457038404 |
San Francisco | 35335.38321167884 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View regr_sxy
query example" %}}
The following example uses the NOAA Bay Area weather data.
SELECT
location,
regr_sxy(temp_min, temp_max) AS temp_regr_sxy
FROM weather
GROUP BY location
location | temp_regr_sxy |
---|---|
Concord | 107454.64233576645 |
Hayward | 54811.06764168191 |
San Francisco | 37101.914233576645 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View stddev
query example" %}}
The following example uses the sample data set provided in Get started with InfluxDB tutorial.
SELECT
room,
stddev(co) AS stddev
FROM home
GROUP BY room
room | stddev |
---|---|
Living Room | 5.885662718931967 |
Kitchen | 9.321879418735037 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View stddev_pop
query example" %}}
The following example uses the sample data set provided in Get started with InfluxDB tutorial.
SELECT
room,
stddev_pop(co) AS stddev_pop
FROM home
GROUP BY room
room | stddev_pop |
---|---|
Kitchen | 8.956172047894082 |
Living Room | 5.654761830612032 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View stddev_samp
query example" %}}
The following example uses the sample data set provided in Get started with InfluxDB tutorial.
SELECT
room,
stddev_samp(co) AS stddev_samp
FROM home
GROUP BY room
room | stddev_samp |
---|---|
Living Room | 5.885662718931967 |
Kitchen | 9.321879418735037 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View var
query example" %}}
The following example uses the sample data set provided in Get started with InfluxDB tutorial.
SELECT
room,
var(co) AS var
FROM home
GROUP BY room
room | var |
---|---|
Living Room | 34.64102564102564 |
Kitchen | 86.89743589743587 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View var_pop
query example" %}}
The following example uses the sample data set provided in Get started with InfluxDB tutorial.
SELECT
room,
var_pop(co) AS var_pop
FROM home
GROUP BY room
room | var_pop |
---|---|
Living Room | 31.976331360946745 |
Kitchen | 80.21301775147927 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View var_samp
query example" %}}
The following example uses the sample data set provided in Get started with InfluxDB tutorial.
SELECT
room,
var_samp(co) AS var_samp
FROM home
GROUP BY room
room | var_samp |
---|---|
Kitchen | 86.89743589743587 |
Living Room | 34.64102564102564 |
{{% /expand %}} {{< /expand-wrapper >}}
Approximate aggregate functions
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.
{{< expand-wrapper >}}
{{% expand "View approx_distinct
query example" %}}
The following example uses the sample data set provided in Get started with InfluxDB tutorial.
SELECT
room,
approx_distinct(co::string) AS approx_distinct
FROM home
GROUP BY room
room | approx_distinct |
---|---|
Living Room | 7 |
Kitchen | 8 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View approx_median
query example" %}}
The following example uses the sample data set provided in Get started with InfluxDB tutorial.
SELECT
room,
approx_median(temp) AS approx_median
FROM home
GROUP BY room
room | approx_median |
---|---|
Kitchen | 22.7 |
Living Room | 22.3 |
{{% /expand %}} {{< /expand-wrapper >}}
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.
{{< expand-wrapper >}}
{{% expand "View approx_percentile_cont
query example" %}}
The following example uses the sample data set provided in Get started with InfluxDB tutorial.
SELECT
room,
approx_percentile_cont(temp, 0.99) AS "99th_percentile"
FROM home
GROUP BY room
room | 99th_percentile |
---|---|
Kitchen | 23.3 |
Living Room | 22.8 |
{{% /expand %}} {{< /expand-wrapper >}}
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).
{{< expand-wrapper >}}
{{% expand "View approx_percentile_cont_with_weight
query example" %}}
The following example uses the sample data set provided in Get started with InfluxDB tutorial.
SELECT
room,
approx_percentile_cont_with_weight(temp, co, 0.99) AS "co_weighted_99th_percentile"
FROM home
GROUP BY room
room | co_weighted_99th_percentile |
---|---|
Kitchen | 23.3 |
Living Room | 22.8 |
{{% /expand %}} {{< /expand-wrapper >}}