SELECT * FROM SYS_USER PROCEDURE ANALYSE() \G;
URL : http://dev.mysql.com/doc/refman/5.0/en/procedure-analyse.html
---
select s1 from tbl_0001
procedure analyse();
+---------------------+-----------+-----------+------------+------------+------------------+-------+-------------------------+--------+------------------------+
| Field_name | Min_value | Max_value | Min_length | Max_length | Empties_or_zeros | Nulls | Avg_value_or_avg_length | Std | Optimal_fieldtype |
+---------------------+-----------+-----------+------------+------------+------------------+-------+-------------------------+--------+------------------------+
| db_item.tbl_0001.s1 | 0 | 1 | 1 | 1 | 483461 | 0 | 0.2651 | 0.4414 | ENUM('0','1') NOT NULL |
+---------------------+-----------+-----------+------------+------------+------------------+-------+-------------------------+--------+------------------------+
mysql> select count(1) from tbl_0001;
+----------+
| count(1) |
+----------+
| 657829 |
+----------+
1 row in set (0.19 sec)
mysql> select s1,count(1) from tbl_0001 group by s1;
+----+----------+
| s1 | count(1) |
+----+----------+
| 0 | 483461 |
| 1 | 174368 |
+----+----------+
2 rows in set (0.36 sec)