BITMAP_NOT

Description

Computes the difference between the first Bitmap and the second Bitmap, and returns the result as a new Bitmap.

Syntax

BITMAP_NOT(<bitmap1>, <bitmap2>)

Parameters

Parameter	Description
<bitmap1>	The first Bitmap
<bitmap2>	The second Bitmap

Return Value

A Bitmap representing the elements in <bitmap1> that are not in <bitmap2>.

Examples

To compute the difference between two Bitmaps:

select bitmap_to_string(bitmap_not(bitmap_from_string('2,3'), bitmap_from_string('1,2,3,4')));

The result will be an empty Bitmap, as all elements in <bitmap1> are also in <bitmap2>:

+----------------------------------------------------------------------------------------+
| bitmap_to_string(bitmap_not(bitmap_from_string('2,3'), bitmap_from_string('1,2,3,4'))) |
+----------------------------------------------------------------------------------------+
|                                                                                        |
+----------------------------------------------------------------------------------------+
1 row in set (0.01 sec)

To compute the difference where <bitmap1> has elements not present in <bitmap2>:

select bitmap_to_string(bitmap_not(bitmap_from_string('2,3,5'), bitmap_from_string('1,2,3,4')));

The result will be a Bitmap containing the element 5:

+----------------------------------------------------------------------------------------+
| bitmap_to_string(bitmap_not(bitmap_from_string('2,3,5'), bitmap_from_string('1,2,3,4'))) |
+----------------------------------------------------------------------------------------+
| 5                                                                                      |
+----------------------------------------------------------------------------------------+
1 row in set (0.01 sec)