mysql explain query

MySQL execution Plan explain detailed 2015-08-10 13:56:27Category: MySQLThe explain command is the primary way to see how the query optimizer decides to execute a query.This feature has limitations and does not always tell the truth, but its output

Transferred from: http://www.cnblogs.com/magialmoon/archive/2013/11/23/3439042.htmlMySQL official manual description of the explain naming document: Https://dev.mysql.com/doc/refman/5.7/en/explain-output.html#explain_select_typeThe recent slow

Directory I. Optimization Overview Ii. query and index optimization Analysis 1. performance bottleneck locating Show command Slow query log Explain analysis Query Profiling Analysis Query   2 Index and Query Optimization Iii. Configuration

When analyzing query performance, it is also useful to consider the explain keyword. The Explain keyword is typically placed in front of a SELECT query statement to describe how MySQL performs a query operation and the number of rows that MySQL

Say 工欲善其事, its prerequisite. Today we will briefly introduce the next explain.Content navigation Id Select_type Table Type Possible_keys Key Key_len Ref Rows Extra Environment ready MySQL

EXPLAIN is used to return a row of information for each table in the SELECT statement. Tables are listed in the order they will be read by MySQL during query processing. EXPLAIN is used to return a row of information for each table in the SELECT

The explanation of mysql explain is clear.Of With the help of explain, you will know when to add an index to the table to use the index to search for records so that select can run faster.If the index is not properly used, you can run analyze table

The explanation of mysql explain is clear.Of With the help of explain, you will know when to add an index to the table to use the index to search for records so that select can run faster.If the index is not properly used, you can run analyze table

In-depth analysis of explain for MySQL Query optimization MySQLexplain BitsCN.com When analyzing query performance, it is also useful to consider the EXPLAIN keyword. The EXPLAIN keyword is generally placed before the SELECT query statement to

Mysql tuning three steps (slow query and explain profile) often encounter some SQL problems in performance tests. In fact, the most problems encountered in performance tests over the past few years are databases, either high I/O or high cpu, Data