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