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

1. MySQL> select bitmap_and_count(bitmap_from_string('1,2,3'),bitmap_empty());
2. +---------------------------------------------------------------+
3. | bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_empty()) |
4. +---------------------------------------------------------------+
5. |                                                             0 |
6. +---------------------------------------------------------------+

9. MySQL> select bitmap_and_count(bitmap_from_string('1,2,3'),bitmap_from_string('1,2,3'));
10. +----------------------------------------------------------------------------+
11. | bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2,3')) |
12. +----------------------------------------------------------------------------+
13. |                                                                          3 |
14. +----------------------------------------------------------------------------+

16. MySQL> select bitmap_and_count(bitmap_from_string('1,2,3'),bitmap_from_string('3,4,5'));
17. +----------------------------------------------------------------------------+
18. | bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('3,4,5')) |
19. +----------------------------------------------------------------------------+
20. |                                                                          1 |
21. +----------------------------------------------------------------------------+

23. MySQL> select bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'));
24. +-------------------------------------------------------------------------------------------------------------+
25. | (bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'))) |
26. +-------------------------------------------------------------------------------------------------------------+
27. |                                                                                                           2 |
28. +-------------------------------------------------------------------------------------------------------------+

30. 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());
31. +-----------------------------------------------------------------------------------------------------------------------------+
32. | (bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'), bitmap_empty())) |
33. +-----------------------------------------------------------------------------------------------------------------------------+
34. |                                                                                                                           0 |
35. +-----------------------------------------------------------------------------------------------------------------------------+

37. 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);
38. +-------------------------------------------------------------------------------------------------------------------+
39. | (bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'), NULL)) |
40. +-------------------------------------------------------------------------------------------------------------------+
41. |                                                                                                              NULL |
42. +-------------------------------------------------------------------------------------------------------------------+

keyword

1. BITMAP_AND_COUNT,BITMAP