maxMap - ClickHouse Documentation

maxMappedArrays

Introduced in: v20.5.0

Calculates the maximum from value array according to the keys specified in the key array.

Passing a tuple of keys and value arrays is identical to passing an array of keys and an array of values.
The number of elements in key and value must be the same for each row that is totaled.

Syntax

maxMappedArrays(key, value)
maxMappedArrays(Tuple(key, value))

Arguments

key — Array of keys. Array(T)

value — Array of values. Array(T)

Returned value

Returns a tuple of two arrays: keys in sorted order, and values calculated for the corresponding keys. Tuple(Array(T), Array(T))

Examples

Usage example

Query

SELECT maxMappedArrays(a, b)
FROM VALUES('a Array(Char), b Array(Int64)', (['x', 'y'], [2, 2]), (['y', 'z'], [3, 1]));

Response

┌─maxMappedArrays(a, b)───┐
│ (['x','y','z'],[2,3,1]) │
└─────────────────────────┘

​maxMappedArrays