bitmap_and_count

bitmap_and_count

description

Syntax

BigIntVal bitmap_and_count(BITMAP lhs, BITMAP rhs, ...)

计算两个及以上输入bitmap的交集，返回交集的个数.

example

MySQL> select bitmap_and_count(bitmap_from_string('1,2,3'),bitmap_empty());
+---------------------------------------------------------------+
| bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_empty()) |
+---------------------------------------------------------------+
|                                                             0 |
+---------------------------------------------------------------+


MySQL> select bitmap_and_count(bitmap_from_string('1,2,3'),bitmap_from_string('1,2,3'));
+----------------------------------------------------------------------------+
| bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2,3')) |
+----------------------------------------------------------------------------+
|                                                                          3 |
+----------------------------------------------------------------------------+

MySQL> select bitmap_and_count(bitmap_from_string('1,2,3'),bitmap_from_string('3,4,5'));
+----------------------------------------------------------------------------+
| bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('3,4,5')) |
+----------------------------------------------------------------------------+
|                                                                          1 |
+----------------------------------------------------------------------------+

MySQL> select bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'));
+-------------------------------------------------------------------------------------------------------------+
| (bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'))) |
+-------------------------------------------------------------------------------------------------------------+
|                                                                                                           2 |
+-------------------------------------------------------------------------------------------------------------+

MySQL> select bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'),bitmap_empty());
+-----------------------------------------------------------------------------------------------------------------------------+
| (bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'), bitmap_empty())) |
+-----------------------------------------------------------------------------------------------------------------------------+
|                                                                                                                           0 |
+-----------------------------------------------------------------------------------------------------------------------------+

MySQL> select bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'), NULL);
+-------------------------------------------------------------------------------------------------------------------+
| (bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'), NULL)) |
+-------------------------------------------------------------------------------------------------------------------+
|                                                                                                              NULL |
+-------------------------------------------------------------------------------------------------------------------+

keywords

BITMAP_AND_COUNT,BITMAP