RB32_TO_BITMAP Function

rb32_to_bitmap(expr)

Overview

The RB32_TO_BITMAP function converts binary data in the standard Roaring Bitmap 32-bit serialization format to a Singdata internal BITMAP type. This function is primarily used for data interoperability with external systems (such as ClickHouse, Druid, and other systems using the standard Roaring Bitmap format).

Syntax

rb32_to_bitmap(expr)

Parameters

• expr: An expression of type BINARY, containing binary data in the Roaring Bitmap 32-bit serialization format.

Return Result

Returns BITMAP type. Returns NULL if the input data is not in valid Roaring Bitmap 32-bit format.

Examples

1. Convert Roaring Bitmap 32-bit binary data to BITMAP:

   SELECT bitmap_to_string(rb32_to_bitmap(unbase64('OjAAAAUAAAAAAAAAAgAAAAgAAAAJAAAACwAAADAAAAAyAAAANAAAADYAAAA4AAAAoty33+27ivbbow==')));
   +---------------------------------------------------------------------------------------------------+
   | bitmap_to_string(rb32_to_bitmap(unbase64('OjAAAAUAAAAAAA...')))                                   |
   +---------------------------------------------------------------------------------------------------+
   | 56482,188343,572397,652938,762843                                                                 |
   +---------------------------------------------------------------------------------------------------+
   

2. Round-trip conversion between BITMAP and Roaring Bitmap 32-bit format using bitmap_to_rb32:

   SELECT bitmap_to_string(rb32_to_bitmap(bitmap_to_rb32(bitmap_build(array(1, 2, 3)))));
   +--------------------------------------------------------------------------------+
   | bitmap_to_string(rb32_to_bitmap(bitmap_to_rb32(bitmap_build(array(1, 2, 3))))) |
   +--------------------------------------------------------------------------------+
   | 1,2,3                                                                          |
   +--------------------------------------------------------------------------------+
   

3. Analyze the conversion result using bitmap functions:

   SELECT bitmap_count(rb32_to_bitmap(bitmap_to_rb32(bitmap_build(array(1, 12, 123, 1234, 12345)))));
   +--------------------------------------------------------------------------------------------+
   | bitmap_count(rb32_to_bitmap(bitmap_to_rb32(bitmap_build(array(1, 12, 123, 1234, 12345))))) |
   +--------------------------------------------------------------------------------------------+
   | 5                                                                                          |
   +--------------------------------------------------------------------------------------------+
   

Notes

• When the input parameter is NULL, the result is NULL.
• When the input binary data is not in valid Roaring Bitmap 32-bit serialization format, the function returns NULL instead of throwing an error.
• The Roaring Bitmap 32-bit format only supports values within the 32-bit unsigned integer range (0 ~ 4294967295). If the Singdata BITMAP contains values beyond this range, bitmap_to_rb32 will return NULL, making round-trip conversion via the 32-bit format impossible. For BITMAPs containing values beyond the 32-bit range, use rb64_to_bitmap / bitmap_to_rb64 for 64-bit format conversion.
• The inverse operation of this function is bitmap_to_rb32, which converts a Singdata BITMAP to the Roaring Bitmap 32-bit serialization format.