explain gigabytes

to access the lower level transaction manager, the storage Manager to manipulate the data, their respective division of labor is different, ultimately by calling the physical layer of the file to obtain the query structure information, the final result response to the application layer. Physical layer, the actual physical disk stored on the file, mainly have a penny data file, log file. By the above description, generating an execution plan is an essential step in executing an SQL, and a SQL pe

Manager to manipulate the data, their respective division of labor is different, ultimately by calling the physical layer of the file to obtain the query structure information, the final result response to the application layer. Physical layer, the actual physical disk stored on the file, mainly have a penny data file, log file. By the above description, generating an execution plan is an essential step in executing an SQL, and a SQL performance can be seen intuitively by looking at the executi

Tags: imp http st table order HDD ons tin tab TEMP table [SQL]View PlainCopyPrint? explain Select * from user Explain select * from user[SQL]View PlainCopyPrint? Explain extended Select * from user Explain extended select * from user Id Select identifier. This i

Use explain to view, as follows1, first create the table test, the statement is as follows[SQL]View Plaincopy Create table Test (a int,b varchar (), c varchar (10)); 2, A and B in the table to create the index, the order is a, a, b[SQL]View Plaincopy Create index idx_a_b on test (A, b); 3. Insert three data into the inside, insert the result as follows:4, use explain query, see

Suddenly whim want to learn MySQL optimization, found a good introduction explain article, the promotion of hope for everyone to help:Article reprinted from: Http://database.51cto.com/art/200912/168453.htmExplain shows how MySQL uses indexes to process SELECT statements and join tables. Can help select better indexes and write more optimized query statements.Using the method, add explain to the SELECT state

Label:In the daily work, we will sometimes slow query to record some long-running SQL statements, to find out these SQL statements does not mean that it is done, we often use the explain command to view the execution plan of these SQL statements, to see whether the SQL statement is used index, There is no full table scan, which can be viewed through the explain command. So we have an in-depth look at the co

Label: MySQL Explain detailed explain shows how MySQL uses indexes to process SELECT statements and join tables. Can help select better indexes and write more optimized query statements. Using the method, add explain to the SELECT statement: such as: ExplainSelectUsername,first_name form Hx,itlearnerwherea.ID=explanation of b.ID

Here we will introduce the MySQL in the explain interpretation of the order, I hope to help you.AD:Explain shows how MySQL uses indexes to process SELECT statements and join tables. Can help select better indexes and write more optimized query statements.Using the method, add explain to the SELECT statement:Such as: Explain select surname,first_name for

1 mysql> explain select count (id) from t_prehandle_zhigao_05 as zhigao where start_time> '2017-05-30 ';2 + ---- + ------------- + -------- + ------- + --------------- + ------------ + --------- + ------ + --------- + ---------------------------- +3 | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |4 + ---- + ------------- + -------- + ------- + --------------- + ------------ + --------- + ------ + --------- + ---

There is no good reason to explain which Linux is more powerful-general Linux technology-Linux technology and application information. The following is a detailed description. Today, I chatted on the Internet and heard some netizens say Ubuntu is the most powerful Linux. At that time, some of them used Fedora and Mandriva to refute it. We mean they have their own expertise, both of them said that they use the most powerful version and also listed some

Explain the network requests under c #. net core, This article is about. net core 1.1 or later in the VS2017 environment. During this period, because. net core is not based on IIS, our previous network Request Code may be incompatible and report errors under the. net core framework. Here we will give a general introduction to How to Make http requests under. net core, mainly the GET and POST methods. If there are any errors, please let me know! First,

Description of the return value of the explain SQL statement performance test: www.2cto.com SQL code mysql> Explain SELECT 'content _ id', 'content _ old_id ', 'content _ hasimg ', 'content _ time_update ', 'content _ title_long', 'vhost _ content '. 'site _ id', 'site _ domain ', 'site _ name ', 'site _ state' FROM 'vhost _ content' left join 'vhost _ site' ON 'vhost _ content '. 'site _ id' = 'vhost _ sit