groupUniqArray

Creates an array from different argument values. The memory consumption of this function is the same as for the uniqExact function.

Syntax

groupUniqArray(x)
groupUniqArray(max_size)(x)

Parameters

• max_size — Limits the size of the resulting array to max_size elements. groupUniqArray(1)(x) is equivalent to [any(x)]. UInt64

Arguments

• x — Expression. Any

Returned value

Returns an array of unique values. Array

Examples

Usage example

CREATE TABLE t (x UInt8) ENGINE = Memory;
INSERT INTO t VALUES (1), (2), (1), (3), (2), (4);

SELECT groupUniqArray(x) FROM t;

┌─groupUniqArray(x)─┐
│ [1,2,3,4]         │
└───────────────────┘

With max_size parameter

SELECT groupUniqArray(2)(x) FROM t;

┌─groupUniqArray(2)(x)─┐
│ [1,2]                │
└──────────────────────┘

Introduced in version 1.1.