GROUP_BITMAP_AND

Introduction

The GROUP_BITMAP_AND function is used to compute the bitwise AND operation on a set of Bitmap data and returns the final result. This function is highly efficient when dealing with large-scale datasets, especially in scenarios where intersection operations on multiple Bitmaps are required. It can directly return the final Bitmap result without intermediate states.

Syntax

group_bitmap_and(bitmap)

Parameters

• bitmap: An expression of type BITMAP, representing the Bitmap data to be operated on.

Return Value

The function returns a result of type INT, representing the result of the bitwise AND operation on all input Bitmaps.

Example

Example 1: Computing the Bitwise AND of Multiple Bitmaps

Assume there is a table t with a column v that stores multiple arrays. Now, we need to compute the result of the bitwise AND operation on these arrays.

SELECT group_bitmap_and(bitmap_build(v)) AS res FROM VALUES (array(1,2,3,4,5,6,7,8,9,10)), (array(6,7,8,9,10,11,12,13,14,15)), (array(2,4,6,8,10,12)) AS t(v);

Result:

3

Example 2: Verifying intersection logic with a smaller dataset

SELECT group_bitmap_and(bitmap_build(v)) AS res FROM VALUES (ARRAY(1, 2, 3)), (ARRAY(1, 2)), (ARRAY(1)) AS t(v); +-----+ | res | +-----+ | 1 | +-----+

Related Functions

• group_bitmap_and_state: Returns the intermediate state of the bitwise AND operation, suitable for scenarios where step-by-step calculations are needed.
• group_bitmap_merge: Merges multiple intermediate state Bitmap objects.
• bitmap_and: Performs a bitwise AND operation on two Bitmaps.
• bitmap_to_array: Converts a Bitmap to an array format for easier result inspection.