BITMAP_UNION_COUNT
Description
Computes the union of input Bitmaps and returns their cardinality.
Syntax
BITMAP_UNION_COUNT(<expr>)Parameters
| Parameter | Description |
|---|---|
<expr> | Supported data types of BITMAP |
Return Value
Returns the size of the Bitmap union, that is, the number of elements after deduplication
Example
select dt,page,bitmap_to_string(user_id) from pv_bitmap;+------+------+---------------------------+
| dt | page | bitmap_to_string(user_id) |
+------+------+---------------------------+
| 1 | 100 | 100,200,300 |
| 2 | 200 | 300 |
+------+------+---------------------------+Calculate the deduplication value of user_id:
select bitmap_union_count(user_id) from pv_bitmap;+-------------------------------------+
| bitmap_count(bitmap_union(user_id)) |
+-------------------------------------+
| 3 |
+-------------------------------------+