sub_bitmap

Description

Syntax

BITMAP SUB_BITMAP(BITMAP src, BIGINT offset, BIGINT cardinality_limit)

从 offset 指定位置开始，截取 cardinality_limit 个 bitmap 元素，返回一个 bitmap 子集。

example

  1. mysql> select bitmap_to_string(sub_bitmap(bitmap_from_string('1,0,1,2,3,1,5'), 0, 3)) value;
  2. +-------+
  3. | value |
  4. +-------+
  5. | 0,1,2 |
  6. +-------+
  8. mysql> select bitmap_to_string(sub_bitmap(bitmap_from_string('1,0,1,2,3,1,5'), -3, 2)) value;
  9. +-------+
  10. | value |
  11. +-------+
  12. | 2,3   |
  13. +-------+
  15. mysql> select bitmap_to_string(sub_bitmap(bitmap_from_string('1,0,1,2,3,1,5'), 2, 100)) value;
  16. +-------+
  17. | value |
  18. +-------+
  19. | 2,3,5 |
  20. +-------+

keyword

  1. SUB_BITMAP,BITMAP_SUBSET,BITMAP