CREATE TABLE tt (i int) ;

INSERT INTO `tt` VALUES (1),(0),(1),(2),(0),(NULL),(1),(2),(NULL),(1),(2);

SELECT  DISTINCT COUNT(*) OVER () FROM tt GROUP BY i ;

SELECT  DISTINCT COUNT(*) OVER (), MOD(MIN(i),2) FROM tt GROUP BY i ;

MariaDB [test]> SELECT  DISTINCT COUNT(*) OVER () FROM tt GROUP BY i ;

+------------------+

| COUNT(*) OVER () |

+------------------+

|                4 |

+------------------+

1 row in set (0.001 sec)

MariaDB [test]> SELECT  DISTINCT COUNT(*) OVER (), MOD(MIN(i),2) FROM tt GROUP BY i ;

+------------------+---------------+

| COUNT(*) OVER () | MOD(MIN(i),2) |

+------------------+---------------+

|                0 |          NULL |

|                0 |             0 |

|                0 |             1 |

+------------------+---------------+

3 rows in set (0.001 sec)

mysql> SELECT  DISTINCT COUNT(*) OVER (), MOD(MIN(i),2) FROM tt GROUP BY i ;

+------------------+---------------+

| COUNT(*) OVER () | MOD(MIN(i),2) |

+------------------+---------------+

|                4 |             1 |

|                4 |             0 |

|                4 |          NULL |

+------------------+---------------+

3 rows in set (0.00 sec)