MySQL

Different from row-level or page-level locking options: · Version (for example, the technology used to insert data in MySQL in parallel), which can be a write operation with many read operations at the same time. This indicates that the database or

The main purpose of this experiment is to analyze the actual operation steps for configuring MySQL (the best combination of PHP and MySQL) Database Synchronization. The information I saw on the relevant website two days ago is quite good, let's

To install mysql, follow these steps: Note that, as shown in the figure, some options are different from the default ones. At the same time, if you re-install mysql, you should first back up the data directory in the mysql Directory, which is the

1. What is an index? Indexes are used to quickly search for records with specific values. All MySQL indexes are saved as B-trees. If no index exists, MySQL must scan all the records of the entire table from the first record until the required

Recently, we have studied the implementation of MYSQL random extraction. For example, to randomly extract a record FROM the tablename table, the general syntax is: SELECT * FROM tablename order by rand () LIMIT 1.However, I checked the MYSQL

The following articles mainly introduce the specific content of MySQL limit query optimization. We all know that MySQL database optimization is very important. Limit is the most commonly used and optimized. MySQL limit greatly facilitates paging.

Since I started my career, I have found that many technical staff and colleagues have consulted the author or on the Internet about how to write LEFT JOIN and its features, and the equivalent connection is generally normal, I wrote a Microsoft SQL

The meanings of the following parameters -A, -- analyze analysis [Analyze given tables]-O, -- optimize optimization [Optimize table]-A, -- all-databases all databases [Check all the database]-- Auto-repair Automatic repair [If a checked table is

After learning some basic operation commands, let's learn how to create a database and a database table. 1. Use the SHOW statement to find out the current database on the server: mysql> show databases; + ---------- + | Database | + ---------- + |

MySQL provides standard SQL mode matching and an extended regular expression based on Unix utilities such as vi, grep, and sed. Format of the pattern match. SQL pattern matching allows you to use "_" to match any single character, while "%" matches

Table_cache specifies the table cache size. When MySQL accesses a table, if there is space in the table buffer, the table is opened and put into it, so that the table content can be accessed more quickly. Check the status values Open_tables and

1. test environment: Cpu: 2 GHZ Memory: 2 GB Lan Open a persistent connection to construct random query conditions.   2. Test Results Data volume: 88171 Qps: query per second       Engine type Domain Name Cache (qps) No cache (qps)

  Mysql master-slave synchronization deployment:   Master: 192.168.2.67 Slave: 192.168.2.211 The slave database of the master node has been running for a period of time.   Master: Vim/etc/my. cnf Server-id = 1 master id Log-bin

This error occurs when you use MySQL-Front to connect to mysql.ERROR 1130: Host 10.5.9.168 is not allowed to connect to this MySQL server1. Change the table. It may be that your account is not allowed to log on remotely, but only on localhost. At

1 MySQL IntroductionReferenceMysql was developed by more than 1985 Swedish boys. Later, they established Mysql AB. At that time, they developed mysql to provide data warehouse services for retailers, this is why mysql is good at querying rather than

Optimizes Linux read performance without using the atime attributeWhen a file is created, modified, and accessed, the Linux system records the time information. Record the last time the file was read. When the system reads files frequently, it will

An interesting thing was found during the recent writing process. Mysql procedure has its own unique processing method when passing parameters. For example, if the parameter is defined as an int, the result is null.Mysql procedure runs

Today, the user access to the voting system of the newly deployed project is very slow. The voting system is based on the PHP environment and uses short connections to access the mysql database. The CPU load of the monitored database PHP server is

Master host: www IP: 192.168.9.124From host: www1 IP: 192.168.9.123 # Download mysqlWget http://dev.mysql.com/get/Downloads/MySQL-5.1/mysql-5.1.58-linux-i686-glibc23.tar.gz/from/ftp://mirror.anl.gov/pub/mysql/ # Install mysqlTar xzf

Query yesterday's data select * from faq where answer_time = date_sub (curdate (), interval 1 day );   Query the data for this month: select name, submittime from enterprise where date_format (submittime, '% Y-% m') = date_format (now (),' % Y-% m