MySQL

Copy Code code as follows: #/USR/SHARE/MYSQL/MY-HUGE.CNF # mariadb configuration File Sample template (huge, mega). # # This file applies to the dedicated database server, memory for 1G-2G # The large system on the machine that mainly runs

1, the logical meaning of varchar (N)Starting with MySQL4.1, n in varchar (n) refers to the maximum number of characters (characters) that can be stored in the field, not the number of bytes. Whether it's a Chinese-English character or a number, or

First, Thread_cache MySQL inside in order to improve the performance of the client request creation connection process, a connection pool is provided, which is the Thread_cache pool, where the idle connection thread is placed in the connection pool

1. Without setting a default value: Copy Code code as follows: SELECT userinfo.id, user_name, role, Adm_regionid, Region_name, Create_time From UserInfo Left JOIN region on userinfo.adm_regionid = Region.id Results: To

MySQL deadlock problem is a lot of programmers in the development of the project often encountered problems, the MySQL deadlock and the solution is as follows: 1, MySQL common storage engine lock mechanism MyISAM and memory using table-level locks

1) Start: Sudo/etc/init.d/mysql start 2) Stop: Sudo/etc/init.d/mysql stop 3) Reboot: Sudo/etc/init.d/mysql restart 4) View log: Cat/var/log/mysql.err Cat/var/log/mysql/error.log 5 does not support Chinese Modify/ETC/

I am free to do nothing, 2014 too pompous, blog also did not write a few, ah ~ ~ ~ With this to record the upcoming 2014 Python operates on a variety of databases all over the street, but I still like my style, it involves other operations, but the

First, determine the version View MySQL version Copy Code code as follows: Mysql-v Or you can log in to MySQL using select version (); or status; Command view Ii. Commencement of work Close MySQL Copy Code code as follows:

Read some text data from MySQL, pay the JS variable for example Copy Code code as follows: But found that Firefox always reported unterminated string literal error. Copy the text into TXT open found a few black box, the original

Like PHP and Perl, MySQL also provides the API used by the C language. The API for C code is published with MySQL. It is included in the Mysqlclient library and enables the C program to access the database. Many of the clients in the MySQL source

Innodb_flush_log_at_trx_commit determines when the transaction log Write,flush Innodb_flush_method determines how the log and data files are write and flush. "Show variables" shows that the variable is empty, which means that the default value is

MySQL Case: Java program Access MySQL error ' OPTION sql_select_limit=xxx ' "Environment description" MySQL version: 5.6.14-56-log percona Server (GPL) Program: Access MySQL database using JDBC driver Mysql-connector-java "Error Message" When

One, demand 1, Virtual User Login As a result of the previous configuration successful postfix+mysql virtual user login, realized the benefits and flexibility of using virtual users, so this time also consider the use of virtual users, and the FTP

Index Nested-loop Join (last) because the access is a secondary index, if the query needs to access the columns on the clustered index, then it is necessary to take the data back to the table, it seems that each record is just one more table

Today, database operations are increasingly becoming a performance bottleneck for the entire application, which is especially noticeable for web applications. It's not just about the performance of the database that DBAs need to worry about, it's

Innodb_autoinc_lock_mode This parameter controls the behavior of the associated lock when inserting data into a table with auto_increment columns;It can be set to achieve performance and security (master-slave data consistency) balance"0" Let's sort

Explore the puzzles of Android soft keyboardDelve into Android Async Essentials HandlerThe essential cornerstone of Android's mainstream frameworkStanding on the shoulder of the source code full solution scroller working mechanismAndroid

Mysql installation-free does not have any root permission, mysql installation-free root 1. Download MySQL Community Server 5.5.41 Linux-Generic Compressed TAR Archive mysql download link 2. decompress the tar package. For example, decompress the

64-bit CentOs7 source code installation mysql-5.6.35 process sharing, First install the dependency package to avoid problems during installation [Root @ bogon liuzhen] # yum-y install gcc-c ++[Root @ bogon liuzhen] # yum-y install cmake[Root @ bogon

SQL basics (1), SQL BASICS ( I. mysql management commands /Applications/XAMPP/xamppfiles/bin/mysql-uroot 1. display all databases Show databases; 2. Enter the mysql database USE mysql; 3. display the currently displayed Library Select database (); 4.