To query the SELECT query statement execution plan using explain

1. Query the SELECT query statement execution plan using explain

Mysql> select * from baba where name = ' FJDSJF ';

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

| ID | name |

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

| 1 | FJDSJF |

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

Query the execution plan for the SQL statement

Mysql> Explain select * from baba where name = ' FJDSJF ' \g;

1. Row ***************************

Id:1

Select_type:simple

Table:baba

Type:all

Possible_keys:null

Key:null

Key_len:null

Ref:null

Rows:2

Extra:using where

1 row in Set (0.00 sec)//The SQL statement does not go index

To increase the index:

Mysql> CREATE index Index_baba on baba (name);

Query OK, 2 rows affected (0.09 sec)

Records:2 duplicates:0 warnings:0

mysql> desc Baba;

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

| Field | Type | Null | Key | Default | Extra |

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

| ID | Int (11) |     YES | |       NULL | |

| name | varchar (30) | YES | MUL |       NULL | |

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

Mysql> Explain select * from baba where name = ' FJDSJF ' \g;

1. Row ***************************

Id:1

Select_type:simple

Table:baba

Type:ref

Possible_keys:index_baba

Key:index_baba

Key_len:33

Ref:const

Rows:1//Search for a row and find the

Extra:using where

2. Learn to use the implementation plan to help

Mysql> help explain

Name: ' EXPLAIN '

Description:

Syntax:

EXPLAIN [Explain_type] SELECT select_options

Explain_type:

EXTENDED

| Partitions

Or:

EXPLAIN Tbl_name

The EXPLAIN statement can be used either as a-to obtain information

about what MySQL executes a statement, or as a synonym for DESCRIBE:

o When you precede a SELECT statement with the keyword EXPLAIN, MySQL

Displays information from the optimizer about the query execution

Plan. That's, MySQL explains how it would process the statement,

Including information about how tables is joined and in which order.

EXPLAIN EXTENDED can is used to obtain additional information.

For information about using EXPLAIN and EXPLAIN EXTENDED to obtain

Query execution plan information, see

Http://dev.mysql.com/doc/refman/5.1/en/using-explain.html.

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To query the SELECT query statement execution plan using explain