Relational Data - Aggregate Functions - Reference - Maxmap

From FojiSoft Docs

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

Syntax 

maxMap(key, value)

or 

maxMap(Tuple(key, value))

Alias: maxMappedArrays

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


Parameters

  • key — Array of keys. Array.
  • value — Array of values. Array.

Returned value

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

Example

Query: 

SELECT maxMap(a, b)
FROM values('a Array(Char), b Array(Int64)', (['x', 'y'], [2, 2]), (['y', 'z'], [3, 1]))

Result: 

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