2020-06-18 08:24:31 +00:00
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toc_priority: 143
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---
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# maxMap {#agg_functions-maxmap}
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Syntax: `maxMap(key, value)` or `maxMap(Tuple(key, value))`
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2020-09-16 14:14:33 +00:00
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Calculates the maximum from `value` array according to the keys specified in the `key` array.
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Passing a tuple of keys and value arrays is identical to passing two arrays of keys and values.
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The number of elements in `key` and `value` must be the same for each row that is totaled.
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2020-06-18 08:24:31 +00:00
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Returns a tuple of two arrays: keys in sorted order, and values calculated for the corresponding keys.
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Example:
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``` sql
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SELECT maxMap(a, b)
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FROM values('a Array(Int32), b Array(Int64)', ([1, 2], [2, 2]), ([2, 3], [1, 1]))
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```
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``` text
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┌─maxMap(a, b)──────┐
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│ ([1,2,3],[2,2,1]) │
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└───────────────────┘
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```
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