Database Administrator

MongoDB-instance connection instructionsConnect to MongoDB through shell You can connect to the MongoDB service by executing the following command. Note: localhost is the host name. This option is required:Mongodb: // localhost When you execute the

Oracle 11g solves the problem of User Password Expiration After using Oracle 11g, often encounter the use of sqlplus login oracle Database prompts "ORA-28002: 7 days after the password will expire" and so on. Search for relevant information. It is

MySQL execution Status Analysis When you feel that MySQL performance is faulty, you will usually first check the current MySQL execution status and use show processlist to view it. For example: The state column information is very important. First,

Compile and install MySQL under the same account Compile and install MySQL under the same account Check whether the old version exists: Rpm-qa | grep mysql Uninstall the old version: Rpm-e mysql # normal deletion Mode Rpm-e -- nodeps mysql # Strong

Easily solve the problem of too many MySQL database connections 1. Maximum number of connections allowed by the MySQL database system max_connections. This parameter can be set. If this parameter is not set, the default value is 100. The maximum

Perfect distributed transaction support for MySQL 5.7 Two Phase Commit Protocol Distributed transactions generally adopt the 2 PC Protocol, which is the full name of Two Phase Commitment Protocol. This Protocol is mainly used to solve the problem of

MySQL displays the name of the connected database By default, MySQL does not display the name of the connected database when using databasename!Mysql> show databases;+ -------------------- +| Database |+ -------------------- +| Information_schema ||

MySQL Tutorial: I/O Memory Optimization Mysql Ver 14.14 Distrib 5.6.19, for Linux (i686) using EditLine wrapper I. mysql directory files Ibdata1: The system tablespace contains data dictionaries, rollback logs, and undolog. (Insert buffer

Saving Oracle learning database data as files It is often necessary to generate documents from data in Oracle databases. Because you prefer the script method, you need to set the format when using spool, the following is a simple example of how to

ASM learning Overview Oracle ASM (Oracle Automatic Storage Management)Oracle ASM is a volume manager and a file system for Oracle database files that supports single-instance Oracle DatabaseAnd Oracle Real Application Clusters (Oracle RAC)

ORA-01012: not logged on Processing SQL> startup nomountORA-01012: not logged onSQL> startupORA-01012: not logged on SQL> shutdown immediateThe ORA-24324: service handle not initialized.ORA-24323: value not allowedORA-01089: immediate shutdown in

SQL Server attaches a database and reports error 5123. Recently, my computer has been upgraded from WIN7 to WIN10. After installing common software and SQL SERVER, attach some test databases and the following error is reported: Figure-1: An

Redis performance test Redis performance testing is achieved by executing multiple commands at the same time. Redis performance testing is mainly implemented through redis-benchmark in the src folder (in Linux)Syntax The basic commands for redis

Principles and basic configurations of Oracle DataGuardRecently, the group is working on a disaster recovery solution for the high availability of Oracle. We chose the "maximum performance" mode of DG without affecting the performance of the master

Compile and install PostgreSQL9.4.1 and phpPgAdmin in CentOS 6.6   Preparations before installation # Yum install readline-devel zlib-devel Download, decompress, compile, and install the source code # Wget https://ftp.postgresql.org/pub/source/v9.4.1

The MySQL restart process cannot be underestimated. The restart of the database seems to be very simple and has no technical skills. This is what I said before. This sentence is simply a pain point of mine. This kind of activity is so technical that

MySQL rolls back the insert statement, leading to a doubling of ibd files' MySQL rolls back the insert statement, which causes the ibd file to increase by a factor of one. A simple test: Start transaction;Insert into tb1 values (3, repeat ('A', 650

Enable MySQL 5.6 to support Emoji expressions Let MySQL support Emoji expressions. We recommend that you use the utf8mb4 character set in advance for MySQL databases involving wireless connections. MySQL 5.6 1 solution: Convert Mysql encoding from

OpenResty Load Balancing MySQL OpenRestyHttps://openresty.org/download/ngx_openresty-1.9.3.2.tar.gz Nginx_tcp_proxy_module needs to be downloaded separatelyHttps://github.com/yaoweibin/nginx_tcp_proxy_module First, extract the above files[Nginx @

MySQL dual-master Configuration MySQL dual-master Configuration Prepare the environment: the server operating system is RHEL6.4 x86_64, to minimize installation. Both host A and host B disable the firewall and SELINUX. The IP addresses are 192.168.13