Returns the middle value in a given column. If number of values are even, MEDIAN returns the average of the two middle values.

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Syntax

MEDIAN(<value>)

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Parameters

ParameterDescriptionSupported input types
<value>The expression used to calculate the median value.DOUBLE PRECISION, REAL, BIGINT, INT

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Return Type

MEDIAN returns a value of type DOUBLE PRECISION.

  • This function ignores NULL values.
  • If the input is empty, the function returns NULL.

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Examples

Example

The following query uses UNNEST to convert an array [1,2,5] into a column, calculates the median value, and returns it as result:

SELECT MEDIAN(a) as result FROM UNNEST(array[1,2,5]) as a;

Returns

result (DOUBLE PRECISION)
2

The previous code example returns the middle element as the median because the number of elements in the array is odd.

Example

The following query uses UNNEST to convert an array [100, NULL, 1, 2, 5] into a column, calculates the median value, and returns it as result:

SELECT MEDIAN(a) as result FROM UNNEST(array[100,NULL,1,2,5]) as a;

Returns

result (DOUBLE PRECISION)
3.5

The previous code example returns the average of the two middle elements after sorting the values, because the number of non-NULL elements is even after ignoring NULL values. The average of the middle elements, 2 and 5, is calculated as : ((2+5)/2).