Mysql Database optimization Tool PROCEDURE analyse

PROCEDURE analyse gives suggestions for optimizing each column of an existing table by analyzing the results of the select query.
The syntax for PROCEDURE analyse is as follows:
SELECT ... From ... WHERE ... PROCEDURE analyse ([max_elements,[max_memory]])

Max_elements (default value 256) analyze the maximum number of different values to look for when each column has a different value.
Analyze also uses this value to check whether the optimized data type should be an enum, if the number of different values in the column exceeds the
The max_elements value enum is not a data type that is recommended for optimization.
Max_memory (default 8192) analyze the maximum amount of memory that may be allocated when finding all the different values for each column

The code is as follows	Copy Code
Eg:select * from Web_member procedure analyse (1)

Sample Program

1

The code is as follows	Copy Code
SELECT * From students procedure analyse (); SELECT * From students procedure analyse (16,256);

The second statement requires procedure analyse () not to suggest that there are more than 16 values or enum types that contain more than 256 bytes, and that the output can be long if there are no restrictions;

2

The code is as follows

Copy Code

------------------------------------------------------------------------------------ mysql> DESC user_ Account +-----------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-----------+------------------+------+-----+---------+----------------+ | USERID | int (a) unsigned | NO | PRI | NULL | auto_increment | | USERNAME | varchar (10) | NO | | NULL | | | Passsword | varchar (30) | NO | | NULL | | | GroupName | varchar (10) | YES | | NULL | | +-----------+------------------+------+-----+---------+----------------+ 4 rows in Set (0.00 sec) Mysql> SELECT * from User_account PROCEDURE analyse (1) G; 1. Row *************************** Field_name:ibatis.user_account. Userid Min_value:1 max_value:103 Min_length:1 Max_length:3 empties_or_zeros:0 nulls:0 avg_value_or_avg_length:51.7500 std:50.2562 Optimal_fieldtype:tinyint (3) UNSIGNED not NULL 2. Row *************************** Field_name:ibatis.user_account. USERNAME Min_value:dfsa Max_value:lmeadors .........................................................

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We can see the Analyze analysis Ibatis.user_account from the first line output. The UserID column has a minimum value of 1, a maximum value of 103, a minimum length of 1,
The maximum length 3 ..., and gives the optimization suggestion of changing the field: It is recommended that the data type of the field be changed to tinyint (3) UNSIGNED not NULL.