to use if

relational database, the Internet-related industry is undoubtedly the most use of MySQL, although we C # Developer a lot of SQL Server, but learning some of the knowledge of MySQL is also necessary, he stone of the mountain.Let's start with an

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

The explain command is the first recommended command to address database performance, and most performance issues can be easily resolved with this command, explain can be used to see how SQL statements are executed, to help select better indexes and

The database used by the company is the MySQL database, and my knowledge of MySQL is just a little bit of learning about PHP at school.I think that as a back-end programmer, in addition to the ability to be able to realize the function,After the

The use of the explain command and the relevant parameter description.Https://dev.mysql.com/doc/refman/5.7/en/explain-output.htmlEXPLAIN Output Columns Column Name Description Id Executes the number

1.SQL Front plus EXPLAIN to SQL levelThe meaning of each propertyIdSerial number of the select querySelect_typeThe type of select query is mainly the difference between common queries and complex queries such as federated queries and

1. TargetL Understand what is optimizedL MASTER the method of optimizing queryL MASTER the method of optimizing database structureL MASTER the method of optimizing MySQL server2. What is optimization?L Arrange resources rationally and adjust system

1. Use the explain statement to view the results of the analysis, such asSelect * from Test1 where id=1;will appear:ID selecttype table type possible_keys key Key_len ref rows Extrawhich Type=const indicates that it was found once

View Execution Time1 show Profiles;2 show variables; see if the profiling is on state;3 If it is off, set profiling = 1;4 execute its own SQL statement;5 show profiles; the execution time of the SQL statement can be found;See how many rows were

Two tables, T1 and T2, have only one field, id int. Insert 1000 records each, and run the following statement:ExplainSELECT t1.id,t2.id from T1 INNER joins T2 on T1.id=t2.idShown below:The explanations are as follows:With the help of explain, you

Source: Persister Links: http://www.blogjava.net/persister/archive/2008/10/27/236813.html With the help of explain, you know when to add an index to the table to use the index to find records and make the select run faster. If some problems

Reproduced from http://blog.sina.com.cn/s/blog_4586764e0100o9s1.html useexplainStatement to see the results of the analysis asExplain select * from Test1 where id=1;will appear:ID selecttype Table type Possible_keys keykey_len ref rows extra

MySQL performance analysis and explain usage knowledge is the main content of this article, and then let us through some practical examples to introduce the process, I hope to be able to help you.1. Use the Explain statement to view the results of

ObjectiveThere was no blog for a while, all day busy, to work, recording courses, happened recently a relatively idle time, to get the MySQL database.About MySQL database, here do not do too much introduction, open source, free and other features

1 useexplainStatement to see the results of the analysis, such asExplain select * from Test1 where id=1;will appear:ID selecttype Table type Possible_keys keykey_len ref rows extra Columnswherein, type=const means that through the index once found,

1 useexplainStatement to see the results of the analysis, such asExplain select * from Test1 where id=1;will appear:ID selecttype Table Type possible_keys key Key_len ref rows extra Columnswherein, type=const means that through the index once found,

With the help of explain, you know when to add an index to the table to use the index to find records and make the select run faster.If some problems arise due to improper use of the index, you can run analyze table to update the table's statistics,

UbuntuOne is a cloud storage service provided by Canonical. It has integrated the latest version of UbuntuOne client in Ubuntu11.04Natty, which is more beautiful and easy to use. If you have not upgraded to Ubuntu11.04Natty, but you want to try the

Swift Burning Brain Gymnastics (i)-Optional nesting PrefaceSwift is actually much more complex than objective-c, and Swift incorporates a number of new features compared to Objective-c, born in the 80 's. It also makes it more difficult for us to

ObjectiveSwift is actually much more complex than objective-c, and Swift incorporates a number of new features compared to Objective-c, born in the 80 's. It also makes it more difficult for us to learn to master the language. But everything is