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