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intersect_count

intersect_count

Description​

A function to find the intersection size of a bitmap, without requiring the data distribution to be orthogonal. The first parameter is the Bitmap column, the second parameter is the dimension column used for filtering, and the third parameter is a variable-length parameter, meaning that different values of the filtering dimension column are taken.

Syntax​

BITMAP INTERSECT_COUNT(bitmap_column, column_to_filter, filter_values)

Parameters​

bitmap_column: the bitmap column to be computed.. column_to_filter: the name of the column to be intersected. filter_values: the different values of the filtered dimension columns.

Return value​

Returns a value of the bigint type.

Example​

mysql>  select intersect_count(user_id, dt, '2020-10-01', '2020-10-02'), intersect_count(user_id, dt, '2020-10-01') from tbl where dt in ('2020-10-01', '2020-10-02');
+--------------------------------------------------------------+------------------------------------------------+
| intersect_count(`user_id`, `dt`, '2020-10-01', '2020-10-02') | intersect_count(`user_id`, `dt`, '2020-10-01') |
+--------------------------------------------------------------+------------------------------------------------+
|                                                            3 |                                              7 |
+--------------------------------------------------------------+------------------------------------------------+