Database Administrator

ORA-12170: TNS: Connection timeout problem solved The virtual machine can access the database normally, but the physical machine connection to the database appeared "ORA-12170: TNS: Connection timeout", you can solve the problem with the following

Configure MySQL Master-Slave replication (Master-Slave) on CentOS) The previous article introduced the installation of MySQL without compiling, which is really convenient. Now let's take a look at how to configure MySQL master-slave replication. For

Online Slave reports 1062 Cases Recently, the online Slave often reported a 1062 error. It broke the ground. Fortunately, Slave has not been used in the business for the time being. That is to say, there is no read/write splitting, so Slave has

Oracle Database basics-Installation I. Basic Database knowledge 1. Concept The Database Management System (DBMS) is a technology used in computers to manage, store, and share data. 2. Category Database development can be divided into the following

MySQL query database size Step 1: First open the Mysql Command line and choose Start Menu> program> MySql-Command line client, as shown in Figure 1-1: Figure 1-1 Step 2: Enter use information_schema 1-2 in the command: Figure 1-2 Step 3: view the

Solution for installing Percona Xtrabackup in CentOS 6.5 Solution for installing Percona Xtrabackup in CentOS 6.5 1. download the latest version of Xtracbackup 2. Installation Yum install perl-DBIYum install perl-DBD-MySQLYum install

Problems caused by table sys. dual being cleared A few days ago, I received a report from the application staff saying that the application could not connect to the database and reported the ORA error. This is an Oracle 9.2.0.8 RAC database (it has

Password maintenance in DataGuard Environment The motivation of this article is a friend's question. He asked me if the password file of the slave database can be directly re-built. I said it is best to copy it. If re-built, there may be some

Migrate the collection data in MongoDB to the MySQL database 1. Export data on mongodb and write expmongo. sh. The shell script is as follows: #! /Bin/shDatestr = 'date' + % Y-% m-% d''/Usr/local/mongodb/mongodb-linux-x86_64-2.4.4/bin/export-im_user-

Error dirname in shell script: Invalid option -- B When writing a Shell script today, an error is reported during debugging. [Oracle @ smidb11 autoawrrpt] $. a. sh dirname: Invalid option -- B please try to execute "dirname -- help" for more

Oracle 11g RAC two-node root. sh execution error: one case Only record the Oracle 11g rac installation process once 1. The installation of multi-path software using RHEL6.5 multipath using udev to configure the ASM shared disk failed. At that time,

Oracle lag () and lead () Functions I. Introduction The lag and lead functions are two offset-related analysis functions. These two functions can be used to retrieve the data of the first N rows of the same field in a query (lag) and the next N rows

Comparison of three common Mysql database engines: mysql Database Engine (Click the blue icon on the top to quickly follow it) ISAM: ISAM is a well-defined and time-tested data table management method. It is designed to take into account that the

For data streams, converting data to the desired format is a key step in data operations. For example, if you want to obtain the operation result after aggregation and sorting, you can perform the conversion operation. Unlike SQL Server 2000 DTS,

In the previous article "Connecting MySQL and other databases with C ++", the author introduced the first method of connecting C ++ to MySQL and other databases-connecting MySQL databases through ADO, this method connects to different databases by

So I decided to migrate all my servers from MySQL to MariaDB. It is easy for Arch users to follow the official news: systemctl stop mysqld  pacman -S mariadb libmariadbclient mariadb-clients  systemctl start mysqld  mysql_upgrade -p 

When you perform a sun cluster dual-host switchover, unexpected power failure, or other situations, the shared disk may sometimes fail to be mounted. You need to use FSCK to repair the shared disk. After the restoration is completed, the database

MySQL is a very popular small relational database management system. Currently, MySQL is widely used in small and medium websites on the Internet. Because of its small size, fast speed, and low total cost of ownership, especially the open source

Oracle database backup and recovery is not accessible to every Oracle database administrator. Oracle Database Backup has three methods, each of which has different recovery features. Therefore, you should integrate database and file system backup,

A "virtual" server composed of two or more physical independent servers is called a cluster server. A MicroSoft service called MicroSoft cluster service (MSC) manages cluster servers. An SQL Server cluster is a virtual Server composed of two or more