BITMAP_TO_RB64 Function

bitmap_to_rb64(expr)

Overview

The BITMAP_TO_RB64 function converts a Singdata internal BITMAP type to binary data in the standard Roaring Bitmap 64-bit serialization format. This function is primarily used for data export and interoperability with external systems (such as ClickHouse, Druid, and other systems using the standard Roaring Bitmap format). Unlike bitmap_to_rb32, this function supports the full value range of Singdata BITMAP and is not limited by the 32-bit unsigned integer range.

Syntax

bitmap_to_rb64(expr)

Parameters

• expr: An expression of type BITMAP, containing Singdata internal BITMAP data.

Return Result

Returns BINARY type, with content being binary data in the Roaring Bitmap 64-bit serialization format.

Examples

1. Round-trip conversion between BITMAP and Roaring Bitmap 64-bit format using rb64_to_bitmap:

   SELECT bitmap_to_string(rb64_to_bitmap(bitmap_to_rb64(bitmap_build(array(1, 2, 3)))));
   +--------------------------------------------------------------------------------+
   | bitmap_to_string(rb64_to_bitmap(bitmap_to_rb64(bitmap_build(array(1, 2, 3))))) |
   +--------------------------------------------------------------------------------+
   | 1,2,3                                                                          |
   +--------------------------------------------------------------------------------+
   

2. Supports values beyond the 32-bit range (greater than 4294967295), which is a key advantage of bitmap_to_rb64 over bitmap_to_rb32:

   SELECT bitmap_to_string(rb64_to_bitmap(bitmap_to_rb64(bitmap_build(array(1, 4294967296, 4294967297)))));
   +--------------------------------------------------------------------------------------------------+
   | bitmap_to_string(rb64_to_bitmap(bitmap_to_rb64(bitmap_build(array(1, 4294967296, 4294967297))))) |
   +--------------------------------------------------------------------------------------------------+
   | 1,4294967296,4294967297                                                                          |
   +--------------------------------------------------------------------------------------------------+
   

3. View the converted binary data using base64 encoding:

   SELECT base64(bitmap_to_rb64(bitmap_build(array(1, 2, 3, 4))));
   +---------------------------------------------------------+
   | base64(bitmap_to_rb64(bitmap_build(array(1, 2, 3, 4)))) |
   +---------------------------------------------------------+
   | AQAAAAAAAAAAAAAAOjAAAAEAAAAAAAMAEAAAAAEAAgADAAQA        |
   +---------------------------------------------------------+
   

Notes

• When the input parameter is NULL, the result is NULL.
• The Roaring Bitmap 64-bit format supports the full value range of Singdata BITMAP and is not limited by the 32-bit unsigned integer range (0 ~ 4294967295). For BITMAP data export scenarios involving values beyond the 32-bit range, bitmap_to_rb64 should be preferred over bitmap_to_rb32.
• The inverse operation of this function is rb64_to_bitmap, which converts binary data in Roaring Bitmap 64-bit serialization format to a Singdata BITMAP.