ARRAY_HISTOGRAM()

All functions > ARRAY > ARRAY_HISTOGRAM()

Returns a frequency histogram of values in an array as an array of value-count pairs.

Signatures

Returns: Array of value-count pairs sorted by value

ARRAY_HISTOGRAM(array: ARRAY<T>) → ARRAY<ROW(value: T, count: BIGINT)>

Notes

• Counts frequency of each distinct value in the array
• Returns array of ROW structures with value and count fields
• Results are sorted by value in ascending order
• NULL values are counted separately
• Empty input may yield NULL or an empty array depending on the execution target
• Useful for analyzing value distributions

See also

• Array functions

Examples

Value counts

SELECT
    f1 := ARRAY_HISTOGRAM(ARRAY[1, 1, 2, 3]) -- Distinct values with counts, sorted by value
;

Edge cases

SELECT
    f1 := ARRAY_HISTOGRAM(ARRAY[]::BIGINT[]) -- Empty array → NULL on DuckDB
;