BITMAP-UNION-INT

Description

Counts the number of distinct values in the input expression. The return value is the same as COUNT(DISTINCT expr).

Syntax

BITMAP_UNION_INT(<expr>)

Arguments

Argument	Description
<expr>	The input expression. Supported types: TinyInt, SmallInt, Integer.

Return Value

Returns the number of distinct values in the column. If there is no valid data in the group, returns 0.

Example

-- setup
CREATE TABLE pv_bitmap (
    dt INT,
    page INT,
    user_id BITMAP
) DISTRIBUTED BY HASH(dt) BUCKETS 1
PROPERTIES ("replication_num" = "1");
INSERT INTO pv_bitmap VALUES
    (1, 100, to_bitmap(100)),
    (1, 100, to_bitmap(200)),
    (1, 100, to_bitmap(300)),
    (1, 300, to_bitmap(300)),
    (2, 200, to_bitmap(300));

select bitmap_union_int(dt) from pv_bitmap;

+----------------------+
| bitmap_union_int(dt) |
+----------------------+
|                    2 |
+----------------------+

select bitmap_union_int(dt) from pv_bitmap where dt is null;

+----------------------+
| bitmap_union_int(dt) |
+----------------------+
|                    0 |
+----------------------+