GROUP_BITMAP_OR

Introduction

The GROUP_BITMAP_OR function is used to perform a bitwise OR 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 union operations on multiple Bitmaps are required. It can directly return the final Bitmap result without intermediate states.

Syntax

group_bitmap_or(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 OR operation on all input Bitmaps.

Usage Example

Example 1: Computing the Bitwise OR 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 OR operation on these arrays.

SELECT group_bitmap_or(bitmapBuild(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); +-----+ | res | +-----+ | 15 | +-----+

Example 2: Verifying union logic with a smaller dataset

SELECT group_bitmap_or(bitmap_build(v)) AS res FROM VALUES (ARRAY(1, 2, 3)), (ARRAY(2, 3, 4)), (ARRAY(3, 4, 5)) AS t(v); +-----+ | res | +-----+ | 5 | +-----+

Notes

1. Input Type: Ensure that the input bitmap is of type BITMAP; otherwise, the function execution will fail.
2. Client Support: Clients may not support directly printing BITMAP type results. If you need to view the results, you can use the bitmapToArray function to convert the Bitmap to an array format.