BITMAP BITMAP_OR(BITMAP lhs, BITMAP rhs)
计算两个输入bitmap的并集,返回新的bitmap.
MySQL > select bitmap_count(bitmap_or(to_bitmap(1), to_bitmap(2))) cnt;
+------+
| cnt |
+------+
| 2 |
+------+
MySQL > select bitmap_count(bitmap_or(to_bitmap(1), to_bitmap(1))) cnt;
+------+
| cnt |
+------+
| 1 |
+------+
BITMAP_OR,BITMAP