Shulou(Shulou.com)05/31 Report--

This article mainly introduces the example analysis of SQL sentence optimization in MySQL, which is very detailed and has certain reference value. Friends who are interested must finish it!

The sql is as follows: sql enforces the into_time index

# Time: 2017-02-14T11:35:01.594499+08:00

# User@Host: oms_ readonly[ oms _ readonly] @ [10.44.xxx.xxx] Id: 41636892

# Query_time: 9.299612 Lock_time: 0.000124 Rows_sent: 20 Rows_examined: 2439330

SET timestamp=1487043301

Select * from customers force index (`into_ time`) where `type` = 1 AND `status` < 7 AND `isarea` = 8 AND `into_ time` show table status like 'customers'\ G

* * 1. Row *

Name: customers

Engine: InnoDB

Version: 10

Row_format: Dynamic

Rows: 2504609

Avg_row_length: 710

Data_length: 1780383744

Max_data_length: 0

Index_length: 1253048320

Data_free: 6291456

Auto_increment: 2546101

Create_time: 2017-01-07 01:59:34

Update_time: 2017-02-14 13:58:17

Check_time: NULL

Collation: utf8_general_ci

Checksum: NULL

Create_options:

Comment:

1 row in set (0.00 sec)

There are about 2.5 million rows in the table. Check that into_time select count (*) from customers where `into_ time` explain select * from customers where `type` = 1 AND `status` < 7 AND `isarea` = 8 AND `into_ time`

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