BITMAP-UNION-INT

Description

Counts the number of distinct values in columns of type TINYINT, SMALLINT and INT. The return value is the same as COUNT(DISTINCT expr)

Syntax

BITMAP_UNION_INT(<expr>)

Parameters

Parameter	Description
<expr>	Supports columns or column expressions of type TINYINT, SMALLINT and INT

Return Value

Returns the number of distinct values in a column.

Example

-- setup
create table pv_bitmap(dt int, page int, user_id bitmap bitmap_union) aggregate key(dt,page) distributed by hash(dt) buckets 1 properties ("replication_num"="1");
insert into pv_bitmap values (1,100,bitmap_from_string('100,200,300')),(1,300,bitmap_from_string('300')),(2,200,bitmap_from_string('300'));

select dt,page,bitmap_to_string(user_id) from pv_bitmap;

+------+------+---------------------------+
| dt   | page | bitmap_to_string(user_id) |
+------+------+---------------------------+
|    1 | 100  | 100,200,300               |
|    1 | 300  | 300                       |
|    2 | 200  | 300                       |
+------+------+---------------------------+

select bitmap_union_int(dt) from pv_bitmap;

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