Database Administrator

High-availability installation of Redis in CentOSHigh-availability installation of Redis in CentOS [x] environment Introduction: Master: T1 Slave: T2 VIP: 192.168.68.45 [X] installing Redis (Master, Slave) Note: The flushall modification before

Solve the Problem of MySQL Slave Synchronization Solution:1. stop the Slave service first: slave stop;2. Check the host status on the master server: Record the value corresponding to File and Position.Mysql> show master status;+ ------------------

Deployment and use of Fabric for MySQL sharded high-availability clusters Fabric is a MySQL cluster management tool developed by Oracle, which has both sharding and read/write splitting. Although I think the current version has many defects, it

MySQL multi-master, multi-active Galera cluster deployment and use Galera is a tool that allows MySQL to synchronize and replicate data. It enables real dual-master and multi-master data. The client connects to different MySQL instances for read and

Using innobackupex to implement full MySQL Hot Backup Purpose Using innobackupex to implement full MySQL Hot Backup Environment OS: CentOS 6.6 32bit Introduction Official Website: https://www.percona.com/ Https://www.percona.com/downloads/XtraBackup/

What happens to MySQL when the disk space is full? Guide What happens to MySQL when the disk space is full? What should I do? What will happen When the disk space is full, MySQL cannot write any data, including writing data to the table and

Summary of commonly used query statements in MySQL Development 1. query numeric data: SELECT * FROM tb_name WHERE sum> 100; Query predicate:>, =, ,! =,!> ,! , = 2. query strings SELECT * FROM tb_stu WHERE sname = 'cricode. com' SELECT * FROM

Oracle tree query start with connect I. IntroductionIn Oracle, start with connect by (prior) is used to query data in a tree structure. Here, start with conditon gives the range of data searches, and connect by gives the conditions for Recursive

MySQL Tutorial: Philosophical Thoughts on unauthenticated users Symptom 1 In the production environment, we occasionally encounter connections such as "unauthenticated user", with load at the database server level, high sys cpu, or thread running

How to evaluate real concurrent sessions in Oracle In Oracle, you can view concurrent sessions in the dba_hist_active_sess_history view. You can use the following script to query the maximum concurrency, current connections, and maximum connections

Case study of OOM kill MySQL caused by insufficient swap space Background: A machine has a memory of 256 GB and 2 mysql instances are installed. Each buffer_pool has 106 GB of memory, totaling 212 GB; A database is migrated to the environment

Php-mcrypt cannot be associated when phpMyAdmin is installed in Linux5.8. 1. install php-mcrypt in yum # No installation method available Originally, CentOS does not support the mcrypt module by default. Therefore, you must try another solution

MySQL 5.7.9 source code compilation and installation instructions I. Environment Description 1. Operating System System Version: RHEL 6.3X64 Operating system installation type: Basic System installation package: gcc-c ++ bzip2 (default) bzip2-devel

Linux Oracle deletes archive logs Oracle reported this error today: ORA-00257 Check that the archive logs of Oracle are full. Solution: Two 1. Increase the archive log size. 2. Delete useless archive logs. (select this solution) In Linux:

MySQL (ICP) index push-down comparison with Oracle The first time I saw this term, I thought of it together with Oracle FPD-filter push-down, but later I found that they were just the same thing, when an index contains all the access fields, you can

MySQL master-slave replication Structure Construction 1. Select two servers as the master and backup databases respectively. 2. log on to the server, Yum install mysql; Yum install mysql-server; 3. Start the server Service mysqld start 4. log on to

Sqoop data export and import commands 1. import data from mysql to hive Sqoop import -- connect jdbc: mysql: // localhost: 3306/sqoop -- direct -- username root -- password 123456 -- table tb1 -- hive-table tb1 -- hive-import-m 1 Here, -- table tb1

MySQL event to implement regular table creation note MySQL event to implement regular table creation note Create a table for the next day every morningDELIMITER //Create procedure test. create_tab_every_day ()BEGINDECLARE '@ I' VARCHAR (15 );DECLARE

Error code: 1100 Table 't_ depart_info 'was not locked with lock tables, tableoftables Analyze the cause of error code generation step by step. Be patient. Step 1: Error description 1 queries executed, 0 success, 1 errors, 0 warnings query: insert

Error code: 1007 Can't create database 'test'; database exists, 1007 exists 1. Error description 1 queries executed, 0 success, 1 errors, 0 warnings query: create database test error code: 1007Can't create database 'test'; database exists