read lock

1. Description:The first is to prepare two servers, one master server (master), the other from the server (Slave), and then to ensure that the master and Slave version of the same and master can not be higher than Slave version, it is generally

Before InnoDB lock, why start transactionInnoDB the release of a lock after a transaction commit/rollback, once the transaction commits/rolls back, the lock in the transaction is automatically freed, InnoDB automatically commits by default

[Email protected] [(None)]> grant replication Slave on * * to'Repl'@'192.168.1.177'Identified by'XXX'; Query OK,0Rows Affected (0.01sec)--Global read lock [email protected][(none)]>flush tables with read lock; Query OK,0Rows Affected (0.02sec)

MySQL's first backup tool mysqldump, we have talked to you in the last article, if you still have doubts, please click MysqldumpMySQL's second backup tool LVM snapshot, so today we'll talk about it. LVM Snapshot Volume Win BeiMysqldump is able to

CentOS6.7 installation mysql5.7.18　　1. Extract to/usr/local directory# TAR-ZXVF Mysql-5.7.18-linux-glibc2.5-i686.tar.gz-c/usr/local2. mysql-5.7.18-linux-glibc2.5-i686 folder renamed to MySQL# cd/usr/local# MV Mysql-5.7.18-linux-glibc2.5-i686/mysql3.

1. Purpose: Resolve client concurrent access to your conflict issues2, the Classification of locks1. Lock type1. Read lock (Shared lock)Query (SELECT): After a lock is read, the table record cannot be changed, but can be queried.2. Write lock (mutex,

Preparatory work:To deactivate the database service:Systemctl Stop Mariadb.serviceCopy the database file from the main library as the From library data:Cp-a-r/data/mysql_data/mysql/*/data/mysql_data/mysql2/Finish copying the boot:Systemctl Start

MySQL's Lock1. Shared lock, which is read lock, can be forced by select ... lock in share mode, the default SELECT statement is unlocked2. Exclusive lock, that is, write lock, you can force write lock by select ... for UPDATE, INSERT, UPDATE, DELETE

First, SQL Optimized 1. Analysis and positioning strategies1. Learn the frequency of SQL execution through show status2, location execution inefficient SQL statement:① through slow log positioning; ② use the show processlist command to view the

In the Oracle relational database, let's take a look at the following question:A transaction: Select from T where ID > Ten and ID B Transaction: Update T Set id = 45000 WHERE id = 4501Two transactions are performed in the following order:A

What do we need to back up? In general, the data that we need to back up is divided into the following Data Binary log, InnoDB transaction log Code (stored procedures, stored functions, triggers, event schedulers) Server

MongoDB Series-Management Mongodb->db.currentop ()Management Mongodb->db.currentop (), is absolutely original ... today, the DBA in the company shares a good view of how control management (leveraging the Inntop tool) is performed for each of the

the lock concept in MySQLDifferent storage engines in MySQL support different locking mechanisms. For example, the MyISAM and memory storage engine with table-level locks, bdb with a page lock, also supports table-level locks, InnoDB storage engine

Wait problems caused by--mysql flush-------------------------------2014/07/13PrefaceIn the actual production environment, a large number of SQL statements are sometimes found to be in waiting for table. State, sometimes it may seem confusing, this

JDBC Transaction controlA transaction is a logical set of actions that make up the units of this set of operations, either all succeed or all are unsuccessful.For example, the transfer, one side more, the other side of the implementation of

The analyzing thread is an analysis of the statistics of the MyISAM table (for example, ANALYZE table). The checking permissions thread is the one that checks whether the server has the required permissions to execute the statement. The Checking

Database Backup is extremely important. If there is no backup, the system will go crazy in the following situations:UPDATE or DELETE whitout where... Table was DROPPed accidentally... INNODB was upload upt... Entire datacenter loses power... From

Mydumper is a multi-threaded export and import tool written in C language, and can ensure consistency between multiple tables. Of course, the more threads, the better (this configuration with the server, etc. Mydumper is a multi-threaded export and

In MySQL, table locks are not deadlocked when table-level locking is used for storage engines. This means that all necessary locks are requested immediately at the beginning of a query and the tables are always locked in the same order. In a table

In MySQL, table locks are not deadlocked when table-level locking is used for storage engines. This means that all necessary locks are requested immediately at the beginning of a query and the tables are always locked in the same order. In MySQL,